THE BRITISH 
 COAL-TAR INDUSTRY 
 
THE BRITISH 
 COAL-TAR INDUSTRY 
 
 ITS ORIGIN, DEVELOPMENT, 
 AND DECLINE 
 
 EDITED BY 
 
 WALTER M. GARDNER, M.Sc., F.I.C. 
 
 PRINCIPAL OF THE BRADFORD TECHNICAL COLLEGE ; EDITOR OF THE 
 "JOURNAL OF THE SOCIETY OF DYERS AND COLOURISTS" 
 
 WITH ILLUSTRATIONS 
 
 PHILADELPHIA 
 
 J. B. LIPPINCOTT COMPANY 
 LONDON : WILLIAMS & NORGATE 
 
V 
 
 CONTENTS 
 
 INTRODUCTION .... vii 
 
 I. 1868. THE ANILINE OR COAL-TAR COLOURS. By W. H. 
 
 PERKIN, F.R.S. (Cantor Lectures) . . i 
 
 II. 1870. THE ARTIFICIAL PRODUCTION OF ALIZARINE. By 
 
 Professor H. E. ROSCOE, F.R.S. . 46 
 
 III. 1879. THE HISTORY OF ALIZARIN AND ALLIED COLOURING 
 
 MATTERS. By W. H. PERKIN, F.R.S. ... 54 
 
 IV. 1880. THE NEWER ARTIFICIAL COLOURING MATTERS 
 
 DERIVED FROM BENZENE. By R. J. FRISWELL, 
 
 F.C.S., F.I.C. ... . 60 
 V. 1881. INDIGO AND ITS ARTIFICIAL PRODUCTION. By Pro- 
 fessor H. E. ROSCOE, LL.D., F.R.S. . . .71 
 VI. 1885. THE COLOURING MATTERS PRODUCED FROM COAL- 
 TAR. By W. H. PERKIN, F.R.S 75 
 
 VII. 1886. RECENT PROGRESS IN THE COAL-TAR INDUSTRY. By 
 
 Professor Sir H. E. ROSCOE, M.P., LL.D., F.R.S. 106 
 VIII. 1886. THE SCIENTIFIC DEVELOPMENT OF THE COAL-TAR 
 COLOUR INDUSTRY. By Professor R. MELDOLA, 
 F.C.S., F.I.C. . . .121 
 
 IX. 1896. THE ORIGIN OF THE COAL-TAR COLOUR INDUSTRY 
 AND THE CONTRIBUTION OF HOFMANN AND HIS 
 PUPILS. (Hofmann Memorial Lecture.) By W. H. 
 PERKIN, Ph.D., D.C.L., F.R.S. , . . 141 
 
 X. 1901. THE SYNTHESIS OF INDIGO. By Professor R. 
 
 MELDOLA, F.R.S., F.I.C. . . 188 
 XI. 1901. THE RELATIVE PROGRESS OF THE COAL-TAR IN- 
 DUSTRY IN ENGLAND AND GERMANY DURING THE 
 PAST FIFTEEN YEARS. By ARTHUR G. GREEN, 
 F.I.C., F.CS. . 189 
 XII. 1901. THE INDIGO CRISIS 204 
 
 XIII. 1902. APPLIED CHEMISTRY, ENGLISH AND FOREIGN. By 
 
 Sir J. DEWAR, M.A., LL.D., D.Sc., F.R.S. . .222 
 
 XIV. 1903. THE RELATION BETWEEN SCIENTIFIC RESEARCH AND 
 
 CHEMICAL INDUSTRY. By Professor R. MELDOLA, 
 F.R.S 227 
 
 349277 
 
vi THE BRITISH COAL-TAR INDUSTRY 
 
 PAGE 
 
 XV. 1905. HISTORY OF THE COAL-TAR COLOUR INDUSTRY 
 BETWEEN 1870 AND 1885. By Professor R. 
 MELDOLA, F.R.S. ... . .228 
 
 XVI. 1906. NOTE ON THE PERKIN JUBILEE . . 232 
 
 XVII. 1908. PERKIN OBITUARY NOTICE. By Professor R. 
 
 MELDOLA, F.R.S. . ... 233 
 
 XVIII. 1908. THE FOUNDING OF THE COAL-TAR COLOUR INDUSTRY. 
 
 By Professor R. MELDOLA, F.R.S. . . 234 
 
 XIX. 1908. LETTER FROM PROFESSOR H. CARO TO PROFESSOR 
 
 R. MELDOLA, MAY 1908 . . . -257 
 
 XX. 1910. TINCTORIAL CHEMISTRY, ANCIENT AND MODERN. 
 
 By Professor R. MELDOLA, F.R.S. . . . 259 
 
 XXI. 1910. PATENT LAW IN RELATION TO THE DYEING INDUSTRY. 
 
 By A. G. BLOXAM, F.I.C. . . 269 
 XXII. 1910. THE COAL-TAR COLOUR INDUSTRY OF ENGLAND: 
 CAUSES OF ITS PROGRESS AND RETARDATION. 
 By I. SINGER 280 
 
 XXIII, 1914. THE ARTIFICIAL COLOUR INDUSTRY AND ITS POSI- 
 
 TION IN THIS COUNTRY. By F. M. PERKIN, 
 Ph.D., F.I.C. . . 298 
 
 XXIV. 1914. THE SUPPLY OF CHEMICALS TO BRITAIN AND HER 
 
 DEPENDENCIES. By Sir WILLIAM A. TILDEN, 
 D.Sc., LL.D., F.R.S. . . 315 
 
 XXV. 1914. BRITAIN AND GERMANY IN RELATION TO THE 
 CHEMICAL TRADE. By WILLIAM R. ORMANDY, 
 D.Sc., F.C.A. . 335 
 
 XXVI. 1914. THE MANUFACTURE OF ANILINE DYES IN ENGLAND. 
 By The Right Hon. Lord-Justice MOULTON, P.C., 
 K.C., F.R.S. . .351 
 
 XXVII. 1915. GERMAN CHEMICAL INDUSTRY THIRTY YEARS AGO. 
 
 By The Right Hon. Sir H. ROSCOE, F.R.S. . 365 
 
 XXVIII. 1915. THE MANUFACTURE OF DYESTUFFS IN BRITAIN. By 
 
 Professor W. M. GARDNER, M.Sc., F.I.C. . . 371 
 XXIX. 1915. THE CHEMICAL INDUSTRIES OF GERMANY. By 
 
 Professor P. FRANKLAND, F.R.S. . . -379 
 
 XXX. 1915. PATENT LAW REFORM. By J. W. GORDON, K.C. . 389 
 XXXI. 1915. THE SUPPLY OF DYEWARES. By Professor R. 
 
 MELDOLA, D.Sc., LL.D., F.R.S. .... 401 
 XXXII. 1915. THE POSITION OF THE ORGANIC CHEMICAL IN- 
 DUSTRY. By Professor W. H. PERKIN, F.R.S. . 407 
 
 INDEX OF NAMES 429 
 
 INDEX OF COLOURING MATTERS 434 
 
 TABULAR AND STATISTICAL INFORMATION . ... 437 
 
INTRODUCTION 
 
 As a side issue of the war the industry of the manufacture 
 of synthetic dyestuffs has been brought prominently before the 
 public during the past twelve months. And this has occurred 
 not because of its magnitude for the annual value of the 
 products used in Britain did not much exceed 2,000,000, 
 but because the products were essential to the carrying on of the 
 great textile industries of the country, and they were chiefly 
 imported from Germany. 
 
 It was quickly recognised that our virtual dependence upon 
 Germany for dyestuffs jeopardised our textile trade and many 
 others, such as the manufacture of paints, which involve the use 
 of pigments ; and the annual value of the industries concerned 
 cannot be less than 220,000,000. The stock of dyewares held 
 in this country is never equal to more than a few months* supply, 
 and the processes involved in their production are of such a 
 nature that the manufacture cannot quickly be improvised. 
 Realising therefore that the resources of private enterprise were 
 unequal to the task of making the necessary provision, the 
 Government appointed a commission of inquiry which eventually 
 resulted in the formation of a State-aided limited company 
 British Dyes Ltd. established to manufacture or otherwise 
 provide synthetic dyestuffs on a scale commensurate with the 
 national requirements. 
 
 The history of the origin and development of the coal-tar 
 colour industry is of great interest not only to the chemist and 
 the student of industrial economics, but also to the politician, the 
 leader of industry, and even to the general reader. To each of 
 
 vii 
 
viii THE BRITISH COAL-TAR INDUSTRY 
 
 these it has a significant message. The industry which originated 
 and received its early development in this country has grown to 
 be one of great profit and importance, but after a period of much 
 prosperity here (1856 to about 1870) it became gradually more 
 and more centralised in Germany, and has latterly been one of 
 her most profitable industries ; the average dividend paid by the 
 six largest manufacturing firms being upwards of 20 per cent, on 
 a nominal capital of about 8,000,000, which represents only a 
 small fraction of the capital actually expended, most of which has 
 been written off out of profits. 
 
 The development in Germany of many other associated 
 industries has been the direct outcome of the success of their 
 dyestuffs industry ; for example, the production of synthetic 
 medicines, scents and flavourings, the manufacture of photo- 
 graphic drugs and of fine chemicals generally, the production of 
 artificial fertilisers and of high explosives, and the incidental 
 production of the necessary reagents such as sulphuric acid and 
 caustic soda on an enormous scale. 
 
 The ramifications of the influence of the coal-tar colour 
 industry in Germany are indeed most astonishing, and a close 
 investigation of the causes of their success will well repay those 
 who are responsible for the future success of British industry. 
 
 It is with the object of affording easily accessible material for 
 such an inquiry that this book has been compiled. It comprises 
 the chief lectures and addresses given in this country on the 
 subject since the establishment of the industry by Perkin in 
 1856 to the present day. The papers are given in chronological 
 order, and the book naturally divides itself into two portions, the 
 first twenty-two papers (pp. i to 297) dealing with the history 
 and development of the industry, and the latter portion (Papers 
 XXIII. to XXXIL, pp. 298 to 427) dealing with the problem as 
 it has presented itself since the outbreak of the war. 
 
 The reasons given for the relative decline of the British 
 industry and its phenomenal development in Germany are 
 numerous and varied. Amongst the former may be mentioned 
 
INTRODUCTION ix 
 
 the supposed lack of well-trained chemists in this country, our 
 admitted early neglect of chemical research, defects in our patent 
 laws, the excise restrictions on alcohol, our fiscal system, want of 
 enterprise and of co-operation amongst the British manufacturers, 
 apathy of successive Governments towards industry (as distinct 
 from commerce), and the early neglect of science by the old uni- 
 versities which is not unconnected with a corresponding ignorance 
 and neglect on the part of our legislators and the general mass 
 of citizens. 
 
 These various topics are all dealt with in one or other of the 
 papers reprinted herein, and they have a direct bearing not only 
 on industries based on organic chemistry such as those men- 
 tioned in a previous paragraph, but have also a profound bear- 
 ing on the general question of the relation of science to industry. 
 And it cannot be too often or too strongly stated that the 
 future of British industry depends on a full utilisation of science 
 in our industries. 
 
 One point which is frequently lost sight of in discussing the 
 reasons for our virtual loss of the coal-tar colour industry is that 
 this industry has not been largely developed in any country other 
 than Germany. If countries differing so widely in fiscal, excise, 
 and patent laws, governmental and public appreciation of science, 
 industrial conditions, etc., as Britain, France, and the United 
 States, are equally unable to develop a particular industry which 
 flourishes in Germany, this appears to point to the existence of 
 some specially favourable set of conditions in Germany rather 
 than to the action of some deterrent condition in Britain. 
 
 The compiler of the book desires to express his great in- 
 debtedness to the authors of the various papers, and to the 
 editors of the journals in which they originally appeared, for their 
 kind permission to reproduce them herein. 
 
 WALTER M. GARDNER. 
 BRADFORD, September ist, 1915. 
 
L: 1868 
 THE ANILINE OR COAL-TAR COLOURS 
 
 BY W. H. PERKIN, F.R.S. 
 
 (Cantor Lectures : Journal of the Society of Arts, 1868, 
 pp. 99, 109, 121) 
 
 I 
 
 COAL TAR, BENZOL, NITROBENZOL, ANILINE, AND 
 ANILINE PURPLE OR MAUVE 
 
 IN this short course of lectures it is my desire to bring before 
 you a somewhat condensed history of the artificial colouring 
 matters, generally known as the " coal-tar colours." By this 
 designation it is not meant to imply that colouring matters 
 actually exist in coal tar, and may, therefore, be extracted from it, 
 but that coal tar is the source of certain products which, when 
 changed by various chemical processes, are capable of yielding 
 coloured derivatives. You will thus perceive that it is important 
 for us to consider the various means employed to obtain the raw 
 materials before giving our attention to the colouring matters 
 themselves. We will, therefore, at once proceed to the considera- 
 tion of "coal tar," its formation and constitution. 
 
 Coal tar consists of the oily fluid formed by the destructive 
 distillation of coal, and is obtained as a secondary product in the 
 manufacture of coal gas. Originally, coal tar was a great 
 nuisance to the gas manufacturer, and it was often a problem to 
 him what he should do with it. I need scarcely say that this state 
 of things is now changed. In the gasworks the coal is distilled 
 in large retorts, sometimes twenty-five or thirty feet in length. 
 They are made of fireclay or iron, and several are arranged in one 
 furnace, or oven, as it is usually termed. Each retort is fitted with 
 an iron mouthpiece, from which a vertical tube rises, the mouth- 
 piece also having a door fastened with a cross-bar and screw. 
 
 i 
 
2 THE BRITISH COAL-TAR INDUSTRY 
 
 When in use these retorts are rapidly filled with coal by 
 means of a proper scoop, and then the doors luted and fixed so 
 as to be airtight. Distillation commences immediately, as the 
 retorts are constantly kept red-hot. The gas and other products 
 which form pass up the front vertical pipe (connected with the 
 mouthpiece), through a bend, and down into a long horizontal 
 tube, called the " hydraulic main/' Here most of the oily pro- 
 ducts condense, and as they accumulate pass on with the gas down 
 the general main and flow into a tank provided for their reception. 
 These oily products constitute " coal tar." The coal gas, leaving 
 this tar behind, passes on to the condensers, and deposits a second 
 but smaller quantity of tar, and is then purified and stored in the 
 gas holders. The gas, however, does not interest us now. 
 
 I am here distilling some coal in a small glass retort, the beak 
 of which is inserted into one of the openings of a three-necked 
 receiver. The second opening is connected with a tube, so that 
 the gaseous products may be examined, whilst the third and lower 
 one is fitted to a small bottle, in which you see we have already 
 obtained a quantity of an oily fluid. This is our coal tar. 
 
 Having now seen how coal tar is produced, we will consider 
 of what it consists. Coal tar is by no means a definite body, 
 but contains a great number of different substances, as a glance 
 at the following table will show : 
 
 TABLE I. PRODUCTS OF THE DISTILLATION OF COAL. 
 
 Name. 
 
 Formula. 
 
 Boiling-point 
 Centigr. 
 
 Hydrogen .... 
 
 
 
 HH 
 
 
 Marsh gas (hydride of methyl) 
 
 
 
 (CH 3 )H 
 
 ... 
 
 Hydride of hexyl . 
 
 
 
 
 (C 6 H 13 )H 
 
 65 
 
 Hydride of octyl . 
 
 
 
 
 (C 8 H 17 )H 
 
 106 
 
 Hydride of decyl . 
 
 
 
 
 (CioH 21 )H 
 
 'S3 
 
 Olefiant gas (ethylene) . 
 
 
 
 
 C 2 H 4 
 
 
 Propylene (tritylene) 
 
 
 
 
 C 8 H 6 
 
 ... 
 
 Caproylene (hexylene) . 
 
 
 
 
 C 6 H 12 
 
 55 
 
 (Enanthylene (heptylene) 
 
 
 
 
 C 7 H 14 
 
 99 
 
 Paraffin 
 
 
 
 
 cjau 
 
 
 Acetylene 
 
 
 
 
 C 2 H 2 
 
 ... 
 
 Benzol 
 
 
 
 
 C 6 H 6 
 
 80-8 
 
 Parabenzol 
 
 
 
 
 C 6 H 6 
 
 97'5 
 
 Toluol . 
 
 
 
 
 C 7 H 8 
 
 no 
 
 Xylol . 
 
 
 
 
 C 8 H 10 
 
 139 
 
THE ANILINE OR COAL-TAR COLOURS 
 
 TABLE I. continued. 
 
 Name. 
 
 Formula. 
 
 Boiling-point 
 Centigr. 
 
 Cumol ...... 
 
 C 9 H 12 
 
 148-4 
 
 Cymol ...... 
 
 C 10 H 14 
 
 1707 
 
 Naphthaline ..... 
 
 C 10 H 8 
 
 212 
 
 Paranaphthaline (anthracene) 
 
 C 14 H 10 
 
 
 
 C TT 
 
 
 Pyren ....... 
 
 ^64 
 
 ^15 4 
 
 ... 
 
 Water 
 
 |H} 
 
 100 
 
 Hydrosulphuric acid .... 
 
 {H} S 
 
 ... 
 
 Hydrosulphocyanic acid 
 
 |(CN)} S 
 
 
 Carbonic oxide ..... 
 
 CO 
 
 
 Carbonic anhydride .... 
 
 C0 2 
 
 . . . 
 
 Bisulphide of carbon .... 
 
 CS 2 
 
 47 
 
 Sulphurous anhydride .... 
 
 SO 2 
 
 - 10 
 
 Acetic acid 
 
 1 (C 2 H 8 0) } 
 
 I2O 
 
 Carbolic acid (phenol) 
 
 {(C 6 ^ 5 )} 
 
 188 
 
 Cresylic alcohol (cresol) 
 
 i<cSk)} 
 
 203 
 
 Phlorylic alcohol (phlorol) . 
 
 { (C 8 H 9 ) } 
 
 ... 
 
 Rosolic acid 
 
 
 ... 
 
 Brunolic acid 
 
 ... 
 
 ... 
 
 
 f^i 
 
 
 Ammonia .... 
 
 
 - 33 
 
 
 (H) 
 
 
 
 ( (C 6 H 5 ) } 
 
 
 Aniline ...... 
 
 
 182 
 
 Pyridine ... . 
 
 (C 5 H 5 )'"N 
 
 II5 
 
 Picoline ... . . 
 
 (C 6 H r )'"N 
 
 T 34 
 
 Lutidine ... . . 
 
 (C 7 H 9 )'"N 
 
 
 Collidine ... . 
 
 (C 8 H n )'"N 
 
 170 
 
 Parvoline ... . 
 Coridine ... . . 
 
 (C 9 H 13 )'"N 
 (C 10 H 15 )'"N 
 
 1 88 
 
 211 
 
 Rubidine ... . 
 
 (C n H ir )'"N 
 
 230 
 
 Viridine ... . 
 
 (C 12 H 19 )'"N 
 
 25 1 
 
 Leucoline ... . 
 
 (C 9 H r )'"N 
 
 235 
 
 Lepidine ... . 
 
 (C 10 H 9 )"'N 
 
 260 
 
 Cryptidine ... . 
 
 (C n H n rN 
 
 256 
 
 Pyrrol .... . 
 Hydrocyanic acid 
 
 HC 5 N 
 
 133 
 
 26-5 
 
4 THE BRITISH COAL-TAR INDUSTRY 
 
 This list, however, does not indicate all the constituents of coal tar, 
 but only those which chemists have up to the present time (1868) 
 succeeded in separating from it ; moreover, when we consider 
 how greatly coal differs in composition, and also that the products 
 vary according to the temperature to which the coal has been 
 submitted, it is evident that coal tar must be an almost endless 
 source of chemical products. Many would perhaps consider 
 this list a perfectly hopeless jumble of names impossible to 
 impress upon the memory ; but, fortunately, chemists are able to 
 classify their products, so that this formidable array of substances 
 may be grouped under three or four different heads only, and, 
 therefore, their relationship being once understood, little diffi- 
 culty is experienced in remembering their names. 
 
 Amongst these products, and at the lower part of this table, 
 you will observe a substance called " aniline." This substance 
 is of great interest to us, being one of the principal sources of 
 the coal-tar colours. Aniline was discovered by Unverdorben, 
 in 1826, amongst the products of the distillation of indigo, and 
 from its property of forming crystalline compounds with acids 
 was called " krystalline." Afterwards Runge obtained it from 
 the distillation of coal, and, because it gave a blue coloration 
 with a solution of chloride of lime, called it " kyanol " or blue 
 oil. Fritsche, still later, obtained aniline by the distillation of 
 indigo with hydrate of potassium, and gave it its present name, 
 derived from anil, the Portuguese for indigo. About this time 
 Zinin discovered a remarkable reaction, by which he obtained 
 aniline from a substance called nitrobenzol ; he called it, however, 
 " benzidam." The products obtained by these different chemists 
 were not at first known to be identical ; and it was not until Dr 
 Hofmann investigated the subject that they were all shown to be 
 the same body, aniline. 
 
 Zinin's process for the conversion of nitrobenzol into aniline 
 consisted in treating the nitrobenzol with an alcoholic solution 
 of sulphide of ammonium ; this was greatly improved upon by 
 Bechamp, who employed a mixture of finely divided iron and 
 acetic acid, in place of sulphide of ammonium. 
 
 This is a brief sketch of the history of aniline up to the time 
 of the discovery of the mauve dye ; it was then purely a 
 laboratory product, and was prepared in very small quantities 
 at the time, and only when required for scientific research. 
 Chemists have always been desirous of producing natural organic 
 
THE ANILINE OR COAL-TAR COLOURS 5 
 
 bodies artificially, and have in many instances been successful. 
 It was while trying to solve one of these questions that I 
 discovered the " mauve." I was endeavouring to convert an 
 artificial base into the natural alkaloid quinine, but my experiment, 
 instead of yielding the colourless quinine, gave a reddish powder. 
 With a desire to understand this peculiar result, a different base 
 of more simple construction was selected, viz. aniline, and in 
 this case I obtained a perfectly black product ; this was purified 
 and dried, and when digested with spirits of wine gave the 
 mauve dye. 
 
 You will perceive that this discovery did not in any way origin- 
 ate from a desire to produce a colouring matter, as is sometimes 
 stated, but in experiments of a purely theoretical nature. 
 
 After showing this colouring matter to several friends, I was 
 advised to consider the possibility of manufacturing it upon the 
 large scale, and was, eventually, induced to make the experiment, 
 though, I must confess, not without considerable fear of the 
 result, especially as my chemical advisers set before me anything 
 but encouraging prospects. In starting this manufacture, the first 
 difficulty was to decide upon the source from which aniline could 
 be obtained at a sufficiently low price. It was at once evident 
 that indigo was by far too costly a product for this purpose. 
 Attention was therefore directed to the extraction of aniline from 
 coal tar, but after very numerous experiments it was found that 
 the difficulty of purifying it was so great, that it was not practi- 
 cable to prepare it at a reasonable price from this product. There 
 was, therefore, but one source left, namely, nitrobenzol ; but to 
 prepare aniline from this body necessitated the establishment of 
 a new manufacture, nitrobenzol at that time not being a com- 
 mercial article, and, although it could be produced in small 
 quantities without much difficulty, yet when tons were required 
 at a limited cost many obstacles presented themselves. 
 
 Having spoken of nitrobenzol, it will be necessary, before 
 proceeding further, to tell you something of the body it is 
 prepared from, and also how it is made in quantity. Nitrobenzol 
 is produced from a derivative of coal tar called benzol you will 
 see it mentioned in the list of coal-tar products. It is composed 
 exclusively of carbon and hydrogen, and is therefore called a 
 hydrocarbon. 
 
 Benzol was discovered by Faraday, in 1825, one year before 
 aniline by Unverdorben. Its existence in coal tar was first 
 
6 THE BRITISH COAL-TAR INDUSTRY 
 
 pointed out by Dr Hofmann, in 1 845, and afterwards Mansfield 
 showed that an almost unlimited supply might be obtained from 
 this source. Benzol is a volatile oil, boiling at a temperature of 
 80- 8 C., nearly twenty degrees lower than water, and is also 
 very inflammable, burning with a smoky flame. When ignited 
 it cannot be extinguished by water, as it floats upon its surface. 
 Its vapour, when mixed with air, is explosive. It is also very 
 dense. This I can easily show you by decanting a small quantity 
 of benzol vapour several times from one vessel into another, and 
 then igniting it. Instances have been known, when distilling 
 benzol in large quantities, and some leak in the apparatus has 
 occurred, so that its vapour has escaped, that it has run along 
 the ground, and been ignited by a furnace situated thirty or 
 forty feet distant, and instantly run back to the apparatus. To 
 illustrate this I will pour some benzol vapour into the top of a 
 slightly inclined trough, fourteen feet long, at the lower end of 
 which is placed a lamp. The vapour will be seen to run gradually 
 down till it reaches the lamp, where it ignites, and the flame in- 
 stantly rushes back to the top of the trough. One of the most 
 remarkable properties of benzol is, that when cooled down to nearly 
 the freezing point of water, it solidifies to a beautiful crystalline 
 mass. This property of benzol is sometimes taken advantage of 
 when it is required in a very pure state, as the impurities which 
 accompany it are fluid, and do not freeze when cooled with ice. 
 
 Benzol is often sold under the name of " benzine collas," for 
 the purpose of removing grease from wearing apparel. But let us 
 consider how benzol is separated from the great number of pro- 
 ducts with which it is associated in coal tar. The first operation 
 consists in distilling the coal tar, just as it comes from the gas- 
 works, in large stills, holding one or two thousand gallons each ; 
 these are often made of old steam-boilers. At first very volatile 
 and light oily products come over, and are collected until their 
 density increases to such an extent that they no longer float upon 
 water. These constitute crude coal-tar naphtha. The distillation 
 is then carried on, and heavy, or, as they are technically termed, 
 " dead," oils are collected, a residue of common pitch being left 
 in the still. This pitch is generally run out, and cast into blocks ; 
 but sometimes the distillation is carried on after the dead oils 
 have been obtained, when a mixture of solid oily products distils, 
 nothing but a kind of coke being left behind. These latter 
 substances, however, do not interest us now. 
 
THE ANILINE OR COAL-TAR COLOURS 7 
 
 The light oil, or crude coal-tar naphtha, is then purified by 
 one or two alternate distillations with steam and treatments with 
 concentrated sulphuric acid. It is thus rendered a colourless 
 fluid. Thus purified, coal-tar naphtha contains, besides benzol, 
 at least four or five other bodies. These, however, mostly differ 
 from benzol in being less volatile ; therefore, the naphtha is again 
 distilled, the first, or more volatile, portions only being collected 
 for benzol. By repeating this process of fractional distillation 
 several times, commercial benzol is obtained. Some manufacturers 
 employ stills of a peculiar construction, which enable them to 
 obtain a good product by a smaller number of distillations. 
 
 Benzol, when treated with fuming nitric acid or aquafortis, 
 undergoes a remarkable change. At first the two fluids mix and 
 become of a dark brown colour and slightly warm ; in the course 
 of a few moments red fumes appear, and the mixture enters into 
 ebullition. During this violent action the colour of the liquid 
 becomes lighter and ultimately changes to orange. If water be 
 now added to this product, the benzol, which is such a light 
 body, will be seen to have completely changed into a dense 
 yellow oil sinking in water. This oil is nitrobenzol. Nitro- 
 benzol was discovered in 1834, by Mitscherlich. It solidifies 
 into a crystalline mass at a temperature of about 3 C. ; its 
 odour is like that of the oil of bitter almonds, and before the 
 introduction of coal-tar colours it was made in small quantities, 
 and sold under the name of Essence de Myrbane, for the purpose 
 of scenting soap. 
 
 From the energy with which benzol is attacked by fuming 
 nitric acid, nitrobenzol at first appeared to be a most difficult 
 product to manufacture on the large scale, and this difficulty 
 seemed the greater when it was found necessary that it should 
 be made at a moderate cost. Moreover, at the time I am now 
 referring to, fuming nitric acid, sp. gr. 1-5, could not be obtained 
 in the market, or only at such a cost as almost to preclude its use. 
 Under these circumstances, two mixtures were experimented 
 with instead of the nitric acid in a very concentrated condition. 
 The first was a mixture of nitrate of sodium and sulphuric acid, 
 the second a mixture of ordinary nitric acid, sp. gr. 1-3, and 
 sulphuric acid. The mixture of sulphuric acid and nitrate of 
 sodium was preferred, and employed on the large scale. 
 
 The first apparatus used in the manufacture of nitrobenzol, 
 for the preparation of aniline for the mauve dye, is shown in 
 
8 THE BRITISH COAL-TAR INDUSTRY 
 
 fig. i. It consisted of a large cast-iron cylinder, a, fitted with a 
 stirrer, b, and closed with a door, c, fastened by a cross-bar and 
 screw, d. This cylinder was capable of holding between thirty 
 and forty gallons. It was provided with two necks, e e : one for 
 the introduction of the benzol and sulphuric acid, which were 
 supplied through a syphon tube ; the other for the exit of 
 nitrous fumes. This last was connected with an earthenware 
 worm, to condense any benzol which might be volatilised by the 
 heat of the reaction. The nitrate of sodium was always intro- 
 duced into the cylinder before the door was fastened up and 
 luted. Until the preparation of nitrobenzol was understood, 
 there was a great amount of uncertainty in its manufacture, and 
 
 FIG. i. 
 
 several explosions occurred, but fortunately without causing any 
 injury to the workmen attending the apparatus. These explosions 
 originated generally from the liberation of too much nitric acid 
 from the nitrate of sodium, by the sulphuric acid, before the 
 formation of nitrobenzol had begun, so that, when it started, the. 
 chemical action set in with such energy that an explosion ensued. 
 After a few of these unpleasant occurrences, however, sufficient 
 experience was obtained to get the manufacture under control. 
 Apparatus of a much more extensive character has since been 
 substituted for the cylinders. 
 
 The process of preparing nitrobenzol with a mixture of 
 sulphuric acid and nitrate of sodium in place of nitric acid may 
 be carried on very well in this apparatus, provided sufficient 
 sulphuric acid be employed to produce an acid sulphate of 
 sodium, as this will be found quite fluid at the close of the 
 
THE ANILINE OR COAL-TAR COLOURS 9 
 
 operation, and can be freely run out at the small outlet. A 
 mixture of strong nitric acid and sulphuric acid is now usually 
 employed for the conversion of benzol into nitrobenzol. In 
 working by this latter method the entire charge of benzol is first 
 introduced through a large opening in the lid ; this is then 
 closed and the stirrer set moving ; the nitric and sulphuric acids 
 are then cautiously run in through small pipes, care being 
 taken not to add too much nitric acid, until the red fumes begin 
 to appear. After all the charge of acids has been added, and the 
 reaction has perfectly ceased, the product is drawn off. At first 
 a mixture of sulphuric and nitric acids runs out, and then the 
 nitrobenzol ; this is collected separately and purified, first by 
 agitation with water, and then rendered perfectly neutral by 
 means of a dilute solution of soda. Should it contain any un- 
 converted benzol this may be distilled off by means of steam. 
 On the Continent manufacturers do not appear to have succeeded 
 well in manufacturing nitrobenzol when it first became a com- 
 mercial article ; their difficulty appears to have arisen from the fact 
 that they experimented in earthenware vessels, which are both 
 dangerous and unsuitable, and it was not until information was 
 obtained from England, I believe, that they were able to produce 
 this body at a moderate price. 
 
 We will now pass on to the processes for converting nitro- 
 benzol into aniline. I have already mentioned that Zinin was 
 the first who discovered that nitrobenzol could be converted into 
 aniline, or, as he termed it, benzidam. His process consisted in 
 treating an alcoholic solution of nitrobenzol with ammonia and 
 sulphuretted hydrogen ; but, although the discovery of this pro- 
 cess was one of great importance from many points of view, still 
 it was very tedious. Bechamp, however, found that by employing 
 a mixture of acetic acid and finely divided iron instead of ammonia 
 and sulphuretted hydrogen, the nitrobenzol was very rapidly 
 converted into aniline, and this process has been found the best 
 yet proposed (1868) for manufacturing aniline in large quantities. 
 Many other reagents have been suggested, such as arsenite of 
 sodium, powdered zinc, etc., but none of them have been found 
 so advantageous as iron and acetic acid. 
 
 In carrying out Bechamp's process, cylinders like those used 
 for nitrobenzol (fig. i) were originally employed. The cylinder 
 was set in brickwork and heated by means of a small furnace, 
 iron borings were first introduced, and the door fixed in its place, 
 
io THE BRITISH COAL-TAR INDUSTRY 
 
 airtight. One neck was connected to the upper extremity of a 
 cast-iron worm by means of a pipe called an adapter ; the second 
 neck being fitted with a syphon-tube, for the introduction of the 
 nitrobenzol and acetic acid. In working on the large scale it is 
 necessary to add the nitrobenzol and acetic acid in small quantities 
 at a time, otherwise the reaction is so violent as to almost burst 
 the apparatus : by working carefully, however, there is no need 
 to fear any difficulties, especially if the stirrer is well used. By 
 the time all the charge has been introduced, a quantity of fluid 
 will have distilled over ; this is returned into the cylinder and 
 the fire lit, and the aniline distilled off. 
 
 The principal change which has taken place in this process 
 consists in using high-pressure or superheated steam for the 
 distillation instead of fire, and working the apparatus by means 
 of a steam-engine instead of by hand. 
 
 Aniline thus obtained is generally redistilled with addition of 
 a little lime or caustic soda, for the purpose of decomposing 
 a body called acetanilide, which is often produced in the manu- 
 facture of aniline, especially if the operation is conducted over a 
 fire instead of with steam. 
 
 Commercial aniline generally appears of a pale sherry colour ; 
 when chemically pure it is colourless, but if kept long it becomes 
 quite brown. It possesses a peculiar odour, which is slightly 
 vinous when the aniline is pure. It burns with a smoky flame, 
 but is not very inflammable : its boiling-point is 182 C. One 
 of its most characteristic reactions is its power of producing a 
 blue or blue-violet coloration with chloride of lime, to which I 
 shall again have occasion to refer. Aniline differs entirely from 
 benzol and nitrobenzol, being perfectly soluble in dilute acids. 
 This is owing to its being an organic base, and forming compounds 
 with acids. Thus with hydrochloric acid it forms hydrochlorate 
 of aniline ; with sulphuric acid, sulphate of aniline, etc. 
 
 We will now, in a very rapid and general way, glance at the 
 chemical changes which take place in converting benzol into 
 nitrobenzol and aniline. 
 
 Benzol, as I have already stated, is a hydrocarbon, i.e. a body 
 composed of hydrogen and carbon only ; it is represented by 
 
 C 6 H 6 . 
 
 This is treated with nitric acid, which contains the elements 
 
 HN0 3 . 
 
THE ANILINE OR COAL-TAR COLOURS n 
 
 The nitric acid acts upon the benzol and introduces its nitrogen 
 and part of its oxygen, at the same time removing hydrogen and 
 forming water. 
 
 HN0 3 + C 6 H 6 = C 6 H 5 N0 2 + H 2 O. 
 
 Nitric acid. Benzol. Nitrobenzol. Water. 
 
 Nitrobenzol, when treated with iron and acetic acid, is converted 
 into aniline by the influence of hydrogen gas, in what is termed 
 the nascent state, or the peculiar condition in which it is when 
 in the act of being liberated from a compound. 
 
 This hydrogen unites with the oxygen of nitrobenzol and 
 removes it as water, and at the same time two atoms of hydrogen 
 combine with the deoxygenated nitrobenzol, forming aniline. 
 
 C 6 H 5 N0 2 + H 6 = C 6 H 7 N + 2 H 2 O. 
 
 Nitrobenzol. Aniline. 
 
 Having now seen the various operations which require to be 
 performed for the production of aniline from coal tar, we are 
 prepared for the consideration of its coloured derivatives. We 
 will, therefore, commence at once with the first of the coal-tar 
 colours, the " mauve " dye. I have already given you the history 
 of its discovery ; I will now tell you how it is made. 
 
 First of all, aniline and sulphuric acid, in the proper propor- 
 tions for the formation of sulphate of aniline, are mixed in 
 a large vat with water, and boiled until perfectly dissolved. 
 Bichromate of potassium is then dissolved in a second large vat. 
 These two solutions, when cold, are mixed in a third and still 
 larger vessel, and allowed to stand one or two days. In this way 
 a large quantity of a fine black precipitate is formed ; this is 
 collected upon shallow filters, well washed with water, and then 
 dried. When dry it is a most unpromising sooty-black powder, 
 and contains various products besides the mauve ; the most 
 troublesome of these is a brown, resinous product, soluble in 
 most of the solvents of the colouring matter itself. 
 
 At first this resinous substance was removed by digestion 
 with coal-tar naphtha previously to the extraction of the colouring 
 matter, which was afterwards effected with methylated spirits 
 of wine, and the solution thus obtained when distilled left the 
 mauve as a fusible bronze-coloured mass. 
 
 When digesting the black precipitate with naphtha or strong 
 spirits of wine, the operation had to be performed in closed 
 vessels under pressure or in connection with a condensing 
 
12 THE BRITISH COAL-TAR INDUSTRY 
 
 arrangement, otherwise large quantities of these valuable solvents 
 would have been lost ; and great difficulty was experienced in 
 getting apparatus perfectly tight, on account of the " searching " 
 character of these fluids. Substitutes had also to be found for 
 the ordinary materials employed by engineers for making good 
 manhole joints, and a number of other matters which are appar- 
 ently of but small importance, but it is remarkable the amount 
 of difficulty and annoyance they caused. The method of ex- 
 traction has, however, been materially improved upon by substi- 
 tuting dilute methylated spirits of wine for strong, as this weaker 
 spirit dissolves only a small quantity of resinous matter but all 
 the colouring matter, so that the digestion with coal-tar naphtha 
 is now found unnecessary. 
 
 The solution of the colouring matter in dilute spirit is placed 
 in a still and the spirit distilled off, the colouring matter remaining 
 behind in aqueous solution ; this is filtered and then precipitated 
 with caustic soda. It is afterwards collected on a filter, washed 
 with water, and drained until of a thick pasty consistence, and, 
 if necessary, dried. 
 
 The solid mauve dissolves very freely in spirits of wine, 
 forming an intensely coloured solution ; it is also soluble to a 
 small extent in water, but the aqueous solution on cooling forms 
 a kind of jelly. 
 
 The formation of the mauve or aniline purple by the action 
 of bichromate of potassium upon sulphate of aniline is a process 
 of oxidation, and since the publication of the original specification 
 at the Patent Office a great number of patents have been taken 
 out for the preparation of this colouring .matter, in which the 
 bichromate has been replaced by other oxidising agents, as per- 
 oxide of lead, permanganate of potassium, peroxide of manganese, 
 chloride of lime, ferricyanide of potassium, chloride of copper, 
 etc. ; but I need not make any special remarks upon these various 
 processes, as experience has shown that bichromate of potassium 
 and a salt of aniline, the reagents first proposed, possess ad- 
 vantages over all others, and are now nearly universally employed 
 for the preparation of aniline purple. The next best process 
 appears to be that of Dale and Caro, in which chloride of copper 
 is employed. 
 
 The affinity of aniline purple for silk or wool is very re- 
 markable, and if I take some wool and pass it through a solution 
 of mauve, you will see how rapidly it absorbs it, even from a 
 
THE ANILINE OR COAL-TAR COLOURS 13 
 
 very dilute solution. Aniline purple is sent into the market in 
 three different conditions, in paste, in solution, and in crystals ; 
 but the latter are very rarely employed, as they are very expensive 
 and do not offer corresponding advantages to the consumer. 
 
 The mauve is the most permanent coal-tar purple known, 
 especially with respect to its power of resisting the action of 
 light. 
 
 I will now endeavour to give you some idea of the approxi- 
 mate amount of the various products we have considered obtain- 
 able from 100 Ibs. of coal, and for this purpose I have arranged 
 them in the following table with their respective weights : 
 
 Ibs. ozs. 
 
 Coal . . 100 o 
 
 Coal tar 
 
 Coal-tar naphtha 
 Benzol . 
 Nitrobenzol . 
 Aniline . 
 Mauve . 
 
 10 12 
 
 o 8 
 
 o 
 
 o 
 
 O 2- 
 O O;- 
 
 You see the smallness of the amount of colouring matter 
 obtainable from coal or coal tar ; but there is fortunately one 
 thing which, to some extent, compensates for this, and that is 
 the wonderful intensity of this colouring matter. 1 will illustrate 
 this remarkable fact. I have here a large carboy containing nine 
 gallons of water, and will now add to this a solution containing 
 one grain of mauve, and illuminate the liquid with the magnesium 
 lamp, and you see the single grain has coloured this large bulk 
 of water. A gallon of water contains 70,000 grains, therefore 
 nine gallons contain 630,000 grains. This solution, then, contains 
 only one part of mauve to 630,000 of water. 
 
 II 
 
 MAUVE, MAGENTA, AND SOME OF THEIR DERIVATIVES 
 
 Aniline purple is sometimes supplied to consumers in a pure 
 and beautifully crystalline condition. This product is found to 
 be a salt of a compound, chemically termed an organic base. 
 This base has been called " mauveine " ; it is composed ex- 
 clusively of carbon, hydrogen, and nitrogen, in the following 
 proportions : 
 
 C 27 H 24 N 4 . 
 
i 4 THE BRITISH COAL-TAR INDUSTRY 
 
 Mauveine, although the base of aniline purple, when in solution 
 is not of a purple but of a dull violet shade, and in the solid 
 state is a nearly black crystalline powder. The moment, however, 
 mauveine is brought in contact with an acid so as to form a salt, 
 its solution changes to a purple colour. This takes place even 
 with that feeble acid, carbonic acid. I have here a dilute solution 
 of mauveine ; you will observe the dull violet colour it possesses, 
 but if my assistant only breathes through it a few moments the 
 carbonic acid of his breath will combine with it, and it will 
 acquire the ordinary colour of aniline purple. 
 
 Mauveine is a most powerful chemical body, and will easily 
 decompose ammoniacal salts. This may be readily seen if some 
 mauveine be heated with chloride of ammonium and a little 
 water, when an abundance of ammonia gas will be evolved, which 
 can be distinguished not only by its odour, but by the white 
 fumes it produces with hydrochloric acid. 
 
 The salts of mauveine are beautifully crystalline, and possess 
 a splendid green metallic lustre. The crystallised commercial 
 product consists of the acetate. Mauveine possesses one of the 
 peculiar properties of indigo. Indigo, when treated with re- 
 ducing agents, such as a mixture of sulphate of iron and lime, 
 is rendered nearly colourless and soluble, but this colourless 
 indigo, when subjected to the oxidising influence of the atmo- 
 sphere, rapidly becomes blue again. I here refer to the indigo 
 vat so much used by dyers. Mauveine, when treated in a 
 similar manner, is also nearly decolourised, changing to a pale 
 brownish-yellow fluid, but the moment this is exposed to the 
 air it assumes its original colour far more quickly than indigo. 
 This remarkable fact may be strikingly illustrated by boiling 
 an alcoholic solution of salt of mauveine with a few strips of 
 zinc, in a sealed tube from which the air has been previously 
 removed. The dark purple solution will gradually lose its 
 colour, and change to a very pale yellowish-brown shade. 
 
 I have a tube containing some aniline purple decolourised in 
 this manner, and now if I open it, the air rushes in and the 
 solution instantly assumes the ordinary purple colour. 
 
 Ordinary indigo is quite insoluble in water, and, therefore, its 
 property of becoming soluble, as well as colourless, when treated 
 with reducing agents, is of great practical value, as the dyer, by 
 immersing his goods in this solution of indigo, and then exposing 
 them to the oxidising influence of the air, gets the colouring 
 
THE ANILINE OR COAL-TAR COLOURS 15 
 
 matter firmly fixed in the fibre of his materials. But as the 
 mauve is already soluble in water, this property has not been 
 found of any practical value. 
 
 Aniline purple, when introduced as a dye, being the first 
 colour of its kind, had to encounter many prejudices, and, on 
 account of its peculiar nature, required the adoption of new or 
 modified processes for its application. These difficulties, however, 
 once overcome, its progress was very rapid. At first it was 
 principally employed by the silk dyer and printer, its application 
 to silk being comparatively easy, but it was not used by the 
 calico-printer till a few years afterwards. 
 
 I distinctly remember, the first time I induced a calico-printer 
 to made trials of this colour, that the only report I obtained 
 was that it was too dear, and it was not until nearly two years 
 afterwards, when French printers put aniline purple into their 
 patterns, that it began to interest British printers. 
 
 It will be seen that to introduce a new coal-tar colour after the 
 mauve was a comparatively simple matter. The difficulty in the 
 manufacture of all the raw materials had been overcome, as well 
 as the obstacles in the way of the practical applications of an 
 aniline colour to the arts. 
 
 We will now turn our attention to a colouring matter which 
 has often been confounded with aniline purple. I have 
 designated it as " Runge's blue," as it was first observed by 
 Runge. I have mentioned that Runge, when he first obtained 
 aniline, termed it " kyanol," or blue oil, on account of the blue- 
 coloured solution it gave with chloride of lime. 
 
 After discovering the mauve, I naturally made experiments 
 with this coloured product of Runge's, to see if it contained 
 aniline purple, but my experiments answered the inquiry in the 
 negative. A few years afterwards, however, I was puzzled by 
 finding that French manufacturers were beginning to produce 
 aniline purple by the agency of chloride of lime and a salt of 
 aniline ; being much occupied at that time, I was unable to look 
 carefully into the matter, and it was not until investigating these 
 apparently opposite results a short time since that I was able to 
 understand them. I will perform Runge's experiments, and for 
 that purpose will take a solution of hydrochlorate of aniline, and 
 add to it a very dilute solution of chloride of lime (taking care 
 not to add too much). The solution is now changing, and 
 getting slightly opaque ; by daylight it has an appearance like 
 
1 6 THE BRITISH COAL-TAR INDUSTRY 
 
 indigo, but if I render it clear by the addition of alcohol, and 
 place it before the magnesium lamp, it is seen to be of a brilliant 
 colour, and nearly pure blue, quite unlike aniline purple. 
 
 I have lately succeeded in obtaining this blue product in the 
 solid condition, by treating a solution of hydrochlorate of aniline 
 with a dilute solution of chloride of lime, and precipitating the 
 resulting colouring matter with common salt ; it is thus obtained 
 in an impure condition, and may be collected upon a filter ; by 
 treatment with cold ether or benzol, a large quantity of brown 
 impurities are separated, the colouring matter being left in the 
 solid condition. This substance dissolves in alcohol, forming a 
 nearly pure blue solution, and is capable of dyeing silk a blue or 
 blue-violet colour. 
 
 An alcoholic solution of Runge's blue behaves with caustic 
 potash quite differently from aniline purple, forming a brownish- 
 red-coloured solution instead of a violet. Therefore, there can 
 no longer be any reason for confounding this body with aniline 
 purple, it being entirely different, both in colour and chemical 
 properties. But as this colouring matter is produced by oxidising 
 hydrochlorate of aniline with chloride of lime, how is it that 
 manufacturers have succeeded in preparing aniline purple from 
 the same reagents ? This question I find is very easy to answer : 
 the manufacturer has gone a step further and boiled his product. 
 Now, if I take a piece of silk dyed with Runge's blue, and 
 instead of boiling it, which would wet it and make it difficult to 
 manipulate, do that which is equivalent steam it a very 
 remarkable change takes place, Runge's blue being changed into 
 the mauve. So, here we have cleared up the mystery, and find 
 that by the action of chloride of lime on hydrochlorate of aniline 
 we first get Runge's blue, and then by heating this blue we 
 change it into mauve. Runge's blue is a very unstable body, 
 and of no practical value, its alcoholic solution changing into 
 mauve in a day or two. This change takes place directly on 
 boiling. 
 
 We must now pass on to another colouring matter, in name 
 well known to all of you I mean magenta, also called roseine, 
 fuchsine, aniline red, and various other names. The discovery 
 of this body and its manufacture were strangely dependent upon 
 the source which had been selected for the preparation of aniline 
 for the mauve. Had the aniline contained in coal tar, or the 
 aniline obtained from indigo, been employed for the preparation 
 
THE ANILINE OR COAL-TAR COLOURS 17 
 
 of the mauve, instead of that prepared from commercial benzol, 
 magenta and its train of coloured derivatives would in all 
 probability have remained unknown to this present day, from the 
 simple fact that magenta cannot be produced from pure aniline, 
 a second body being also required. 
 
 You will observe, by reference to the table of coal-tar products, 
 that next to benzol there is a substance named toluol, a substance 
 having a boiling-point not very much above that of benzol. On 
 this account toluol is always contained in commercial benzol, and 
 it possesses most of its properties. With nitric acid it forms 
 nitrotoluol, very similar to nitrobenzol ; with iron and acetic 
 acid it is converted into a base, toluidine, very similar to aniline, 
 except that it is solid instead of liquid when pure. Therefore, 
 aniline prepared from commercial benzol always contains a little 
 toluidine, and this is the second body requisite for the formation 
 of magenta. 
 
 An apparatus for the fractional distillation of coal-tar naphtha 
 has been devised, so that its constituents may be almost com- 
 pletely separated from each other, and thus pure benzol or pure 
 toluol may be obtained. 1 Having obtained these hydrocarbons, 
 pure aniline and pure toluidine may be prepared and then mixed 
 in the most suitable proportions for manufacturing magenta. 
 This process is not very generally employed, however, but the 
 quality of the mixture of aniline and toluidine is determined by 
 distillation, noting the quantities which come over at different 
 temperatures. The necessity of toluidine as well as aniline for 
 the production of magenta was discovered by Dr Hofmann, who 
 found that it could not be produced by perfectly pure aniline, 
 nor perfectly pure toluidine, but that a mixture of these two 
 bases yielded it in quantity. Magenta was apparently first 
 observed by Natanson in 1856, when examining the action of 
 chloride of ethylene on aniline, and afterwards by Dr Hofmann 
 in 1858, when studying the action of tetrachloride of carbon 
 on aniline ; but industrially the discovery of magenta was made 
 by M. Verguin, of Lyons, in 1859, three years after the mauve. 
 M. Verguin's process consisted in treating commercial aniline with 
 a fuming liquid, called tetrachloride of tin, and was first carried 
 out by Messrs Renard Brothers, of Lyons. Since 1859 patents 
 have been taken out for the production of this colouring matter 
 with aniline, and almost all chemicals known, whether capable 
 
 1 See Clarke's Eng. Pat., 5th June 1863, No. 1405. 
 
 2 
 
1 8 THE BRITISH COAL-TAR INDUSTRY 
 
 or incapable of forming magenta. I may mention one process 
 which was extensively employed, and is still used to some extent 
 in Germany, and that is the method of making magenta with 
 commercial aniline and nitrate of mercury. With care this 
 process works very well, and the colouring matter produced is 
 of good quality. When first introduced, magenta prepared by 
 this method was not purified, but sent into the market in a crude 
 form, so that before using it the dyer had to extract it with water. 
 In the preparation of magenta by this process, all the mercury 
 of the nitrate of mercury employed is recovered in the metallic 
 state ; but although this process may possess some advantages, 
 yet the use of mercury salts is most undesirable, on account of 
 their fearfully deleterious influence upon the workmen. 
 
 The process which has almost superseded all others involves 
 the use of arsenic acid, as proposed by Medlock, and patented 
 by him in January 1860. This patent is notorious for the 
 amount of litigation it has caused, showing that a patentee should 
 not only be a discoverer but a lawyer, and even more, and able 
 to discover precisely how much to claim and disclaim in his 
 patent, and also to arrange his specification so that the intellects 
 of the whole world may not be able to discover a single flaw in 
 his description ; and it is a misfortune common to inventors who 
 wish to thoroughly protect themselves, to find that they have 
 claimed too much. 
 
 The manufacture of magenta, as now carried on, is a very 
 simple process ; it is conducted in an apparatus somewhat 
 similar to that represented by fig. 2. 
 
 This apparatus consists of a large iron pot, a, about 4 ft. 
 diameter, set in a furnace of brickwork ; it is provided with a 
 stirrer, b y worked by hand. All the gearing for this stirrer is 
 fixed to the lid, so that stirrer, lid, and all may be lifted away 
 by means of a crane, or other suitable apparatus. There is also 
 a bent tube fixed into the lid, and connected to a condensing 
 worm, d y by means of a joint, which can be made or broken at 
 pleasure. In preparing magenta, a quantity of aniline, containing 
 about 25 per cent, of toluidine, and a nearly saturated solution 
 of arsenic acid, are introduced into this apparatus, and well mixed 
 by working the stirrer ; the proportions of the materials are in 
 about the ratio of i of aniline to 1-5 of a 75 per cent, solution 
 of arsenic acid. When these are well mixed the fire is lighted. 
 After the product has been heated for some time, water begins 
 
THE ANILINE OR COAL-TAR COLOURS 19 
 
 to distil over, then aniline and water, and lastly nearly pure 
 aniline. 
 
 This operation requires some hours for completion, and this 
 is determined by inserting an iron rod, from time to time, and 
 drawing out a portion of the product for examination, as well as 
 by the amount of aniline which distils over. When the heating 
 has been completed, a steam pipe is introduced into the apparatus 
 and steam blown through the fused mass ; by this means an 
 additional quantity of aniline is separated. The lid is then 
 liberated and lifted, with the stirrer, from the apparatus, and 
 the product left to cool before it is removed. A more elaborate 
 
 FIG. 2. 
 
 and larger apparatus is sometimes used, which possesses con- 
 siderable advantages over the smaller one. The iron pot is 
 larger, and is provided with an outlet at the side, which is closed 
 during the operation, and the shaft of the stirrer is hollow 
 (as in the aniline apparatus described previously), and worked 
 by steam. When the operation of heating is concluded, steam 
 is blown down the shaft, and after the addition of water the 
 product is boiled and run out of the outlet in the side of the 
 pot ; by this arrangement it is unnecessary to disconnect the 
 lid of the apparatus, and the product does not require to be 
 removed by mechanical means, as with the apparatus described 
 above. 
 
 The crude product obtained by heating aniline and arsenic 
 acid is next transferred to vats, boiled with water, and filtered. 
 
20 THE BRITISH COAL-TAR INDUSTRY 
 
 Common salt is then added, which precipitates the crude 
 magenta ; this is collected and dissolved in boiling water, again 
 filtered, and the solution, on cooling, deposits the colouring 
 matter in the crystalline condition. This, when recrystallised, 
 constitutes commercial magenta. 
 
 Commercial magenta consists of brilliant crystals, sometimes 
 half an inch in length, having a beautiful golden-green metallic 
 appearance ; these dissolve in warm water almost entirely, forming 
 an intense purplish-red solution. Dr Hofmann has carefully 
 studied the chemical nature of magenta, and has found it to 
 consist of the salt of an organic base, which he has called 
 rosaniline. This base may be obtained from the commercial 
 product, by dissolving it in water and boiling it with an alkali, 
 or alkaline earth, such as ammonia, potash, or lime ; it is thus 
 rendered nearly colourless, and after filtration rosaniline separates 
 from the clear solution, on cooling, in colourless crystals. It 
 is composed of carbon, hydrogen, and nitrogen when anhydrous, 
 but generally contains an equivalent of water also. The 
 anhydrous base has the formula 
 
 This colourless base immediately becomes dark red upon 
 combining with an acid, as I can show you by heating some with 
 acetic acid, when the colour is immediately developed. The 
 magenta produced by heating commercial aniline with nitrate 
 of mercury is the nitrate of rosaniline ; that produced with 
 arsenic acid is the arseniate, but in the process of purification 
 this latter salt becomes converted into hydrochlorate, which is 
 the salt most generally found in the market. Other salts are 
 also commercially manufactured, such as the oxalate and the 
 acetate, especially when a very pure product is required ; these 
 salts are generally prepared from pure rosaniline, by combining 
 it with the required acid, and crystallising from water. 
 
 The acetate of rosaniline crystallises in magnificent octahedra, 
 possessing the ordinary golden-green metallic lustre to a very 
 high degree ; it is also the most soluble salt of rosaniline known. 
 The affinity of magenta for animal fibres is very great ; it does 
 not, however, resist the action of light nearly to the same extent 
 as the mauve. All the derivatives of rosaniline also possess a 
 very great affinity for animal fibres, in most cases quite equal to 
 that of magenta itself. 
 
THE ANILINE OR COAL-TAR COLOURS 21 
 
 When speaking of aniline purple, I showed you that by 
 reducing agents it became colourless, or nearly so, but that the 
 original colour was developed when it was exposed to the oxygen 
 of the air. Salts of rosaniline or magenta are also decolourised 
 by reducing agents, but, unlike aniline purple, the colour is not 
 restored by exposure to the air. Dr Hofmann has found that 
 in this case a new organic base is produced which he has called 
 leucaniline. This substance differs only from rosaniline in con- 
 taining an additional quantity of hydrogen. It may be recon- 
 verted into rosaniline by oxidising agents such as bichromate 
 of potassium, etc. 
 
 There is another very peculiar reaction of rosaniline. This 
 base when brought in contact with hydrocyanic acid, instead of 
 forming a coloured hydrocyanate of rosaniline, yields a perfectly 
 colourless body, which is not a salt but a base. This remarkable 
 fact was discovered by Dr Hugo Milller, and he has called this 
 new body hydrocyanrosaniline. We shall have occasion to refer 
 again to this substance and leucaniline. 
 
 In the formation of magenta, a second product is obtained, 
 commercially called phosphine. This substance was first intro- 
 duced by Mr E. Nicholson. Dr Hofmann has investigated it, 
 and found it also to contain an organic base, which he has 
 called chrysaniline. 
 
 Phosphine or chrysaniline is not capable of being produced at 
 will, and the quantity formed in the manufacture of magenta is 
 variable. In shade it is of rather a yellow orange. This 
 colouring matter differs from rosaniline, the base of magenta, 
 in exactly the opposite direction to leucaniline, containing two 
 atoms less of hydrogen. Leucaniline, rosaniline, and chrysaniline 
 are thus related : 
 
 Leucaniline C 20 H 21 N 3 
 
 Rosaniline C 20 H 19 N 8 
 
 Chrysaniline ...... C 20 H 17 N 3 
 
 The principal use of phosphine is for the formation of a 
 scarlet with magenta. It is not converted into magenta, nor 
 decolourised with reducing agents or hydrocyanic acid, and 
 therefore does not seem to be of the same class of colouring 
 
 ... & 
 
 matters as rosaniline. 
 
 From the residues obtained in the manufacture of magenta 
 three new colours have been obtained by Messrs Girard and 
 De Laire, but, I am sorry to say, my time will not allow me to 
 
22 THE BRITISH COAL-TAR INDUSTRY 
 
 enter into the particulars of these products. I believe they have 
 not been commercially introduced as yet. 
 
 Magenta is now more used as a source of other colours than 
 as a dye. This has caused its manufacture to be conducted on 
 a very extensive scale, and it is now looked upon by the 
 manufacturer as a raw material much in the same way as aniline 
 was regarded in the early days of aniline purple. 
 
 We will next consider some of the derivatives of magenta, 
 and the first we will study is aniline blue or bleu de Lyon. If 
 aniline be treated with a salt of rosaniline or magenta, a remark- 
 able change takes place : at first the colour gradually becomes 
 purple, but afterwards gets quite blue, ammonia being evolved 
 at the same time. This peculiar reaction was observed by MM. 
 Girard and De Laire, who found that this change of colour was 
 due to the formation of a new body, which they termed the bleu 
 de Lyon ; intermediate products were likewise obtained, to which 
 we shall refer presently. MM. Girard and De Laire patented their 
 process in January 1 8 6 1 . This new aniline blue is one of the most 
 important of the artificial colouring matters, and its manufacture 
 has been very much improved upon since its discovery. There 
 are several circumstances which materially influence the beauty 
 of its tint, such as the quality of the aniline and the particular 
 salt of rosaniline employed in its manufacture. It is found by 
 experience that the aniline should be as pure and free from 
 toluidine as possible, and that the salt of rosaniline should 
 contain a feeble acid, such as the acetate, valerate, oleate, or 
 benzoate ; but why the latter is necessary chemists are unable to 
 understand at present. Practically, the various salts of rosaniline 
 required for the manufacture of the blue are not prepared 
 separately, but are produced in the operation by double decom- 
 position, which is simply a process of exchange ; thus, if acetate 
 of rosaniline is required, a mixture of hydrochlorate of rosaniline 
 and acetate of sodium is employed ; these react on each other, 
 and change into acetate of rosaniline and chloride of sodium. 
 
 Aniline blue is manufactured in enamelled iron pots heated 
 by an oil bath. A mixture of magenta, acetate of sodium, and 
 aniline is introduced into the pots, the aniline being employed 
 in excess. When charged the oil bath is heated up to 190 C., 
 and kept near that temperature. At first the red colour of the 
 mixture changes slowly, but afterwards with rapidity. The 
 progress of the operation is ascertained by removing the wooden 
 
THE ANILINE OR COAL-TAR COLOURS 23 
 
 plug, and withdrawing a small quantity of the product upon the 
 end of an iron or glass rod, and it is considered complete when 
 a good blue colour has been obtained ; to ascertain this point 
 with precision, considerable experience is necessary. The excess 
 of aniline distils during this operation, and is condensed by the 
 worm, and collected in a suitable receiver, so that it may be 
 used again. 
 
 From the crude blue product thus obtained, which is a fluid 
 of the consistency of treacle, all the different qualities of blues 
 found in the market are prepared. The cheaper qualities are 
 obtained by simply treating the crude product several times with 
 hydrochloric acid. This removes all the free aniline, and most 
 of the red and purple impurities. Another similar but more 
 effective process is employed for the preparation of the better 
 qualities, and consists in mixing the crude product with methy- 
 lated spirits of wine, and pouring it into water acidulated with 
 hydrochloric acid, and then thoroughly washing with water the 
 colouring matter which it precipitates. But for the purest kinds 
 of blue there are several processes employed ; these are based 
 upon the difficult solubility of some of its compounds in alcohol. 
 In preparing these very pure qualities of blue, instead of starting 
 with the crude product, one of the purified blues is taken. 
 
 Aniline blue, or "bleu de Lyon," is supplied to consumers 
 as a coarse powder having a coppery lustre, or in alcoholic 
 solutions ; it is nearly insoluble in water, and has to be dissolved 
 in alcohol before it is added to the dye bath. 
 
 The nature of this blue has been determined by Dr Hofmann. 
 It is found to contain, like magenta, a colourless base, becoming 
 blue only upon combining with acids. Dr Hofmann has shown 
 this base to contain 
 
 ^88"tl^'t 
 
 and has called it " triphenylrosaniline." Like rosaniline, it 
 becomes colourless when treated with nascent hydrogen, forming 
 a new base, giving colourless salts, as leucaniline. The com- 
 position is 
 
 CsgH^Ng. 
 
 The insolubility of aniline blue in water has been found a 
 great drawback to its use, because when employed for dyeing it 
 is thrown out of solution in the dye bath, and then mechanically 
 adheres to the goods, so that it afterwards rubs off. 
 
24 THE BRITISH COAL-TAR INDUSTRY 
 
 Mr Nicholson has, however, discovered a process for rendering 
 this blue perfectly soluble in water. His process closely corre- 
 sponds to that employed to render indigo permanently soluble. 
 This, it will be remembered, is effected by subjecting indigo to 
 the action of concentrated sulphuric acid, whereby a sulpho acid 
 is produced. 
 
 Mr Nicholson has found that aniline blue, when treated by a 
 similar process, also forms a sulpho acid, perfectly soluble in 
 water, and forming with alkalies nearly colourless solutions. 
 These, however, when decomposed by acids, change back to the 
 original blue. 
 
 This soluble blue is now much used for silk- dyeing, but by 
 dyers it is not thought to be so fast as the normal compound. 
 By some modification of the process just described, Mr 
 Nicholson has obtained another soluble blue, commercially 
 known as " Nicholson's blue." This is now very extensively 
 employed in Great Britain for wool-dyeing, but its application 
 does not appear to be well understood in France and Germany, 
 so that its use there is not so great as in our own country. 
 
 If a salt of rosaniline and aniline be heated together, and the 
 process stopped before aniline blue is produced, the resulting 
 product when treated with dilute acid gives a colouring matter, 
 which has been called "violet imperial." This was at first 
 supposed to consist of a mixture of blue and magenta, but 
 recent research has shown it to consist of intermediate products. 
 Very large quantities of this colouring matter have been used, 
 but its consumption is now rapidly falling off, owing to the 
 introduction of the new violets, about to be described. A few 
 months after the discovery of aniline blue, another colouring 
 matter, called the " bleu de Paris," was obtained by MM. 
 Persoz, de Luynes, and Salvetat. These chemists found that 
 when aniline was heated with tetrachloride of tin for thirty hours 
 to 1 80 C. in a sealed tube, neither a red nor a violet, but a very 
 pure blue, was produced. This colouring matter is generally 
 described as being identical, or probably identical, with the " bleu 
 de Lyon." These blues are, however, widely different in their 
 chemical nature, as the " bleu de Paris " is easily soluble in water, 
 and crystallises freely in needles of a blue colour, with a coppery 
 reflection. It consists of the hydrochlorate of an organic base, 
 which is precipitated from its solution by alkalies as a purplish- 
 blue powder ; it dyes silk readily, and retains its blue colour by 
 
THE ANILINE OR COAL-TAR COLOURS 25 
 
 artificial light. It is remarkable that the discoverers of the " bleu 
 de Paris " do not seem to have observed its difference from the 
 bleu de Lyon." 
 
 I have prepared some of this product with a view to its 
 examination, but hitherto have been prevented from determining 
 its composition. I hope to do so soon. 
 
 The " bleu de Paris " is, unfortunately, difficult to prepare in 
 large quantities, and has never been introduced commercially. 
 
 The recognition of the nature of the " bleu de Lyon," by Dr 
 Hofmann, led him to study the action of a class of substances 
 upon rosaniline, known to chemists as the iodides of the organic 
 radicals ; this investigation resulted in the discovery of the 
 brilliant colours known as the Hofmann violets, and of which so 
 many shades can be obtained, from a very red purple to a nearly 
 pure blue. 
 
 The substances generally used for the preparation of the 
 Hofmann violets from rosaniline are the iodides of methyl and 
 ethyl : the iodide of methyl differs from that of ethyl in a 
 practical point of view, in being rather quicker in its action ; it 
 is also more volatile. Both these substances contain a remarkable 
 element called iodine. This body is found in sea-water and sea- 
 weed ; its aspect is very similar to that of a metal ; one of its 
 characteristic properties is that when heated it volatilises and 
 produces a beautiful purple-coloured vapour, and here we find 
 how dangerous a little knowledge is when relied upon. When 
 the iodide of ethyl, which, as I have told you, contains iodine, 
 was introduced for the preparation of the Hofmann violets, it 
 was stated in some of our periodicals or daily papers, I do not 
 remember which, that chemists had at last succeeded in fixing 
 the colour of iodine, whereas the iodine has nothing whatever 
 to do with the colours produced with the iodides of ethyl and 
 methyl, but is simply an instrument in bringing about the change 
 which takes place in their formation ; moreover, these colours 
 can be equally produced without using iodine at all. It is 
 unfortunate that the popular reports upon scientific matters are 
 generally so utterly untrustworthy. One of the most remarkable 
 reactions of iodine is the blue-violet colour it gives with a solution 
 of starch ; this is used as a test for its presence when in the free 
 condition, and is remarkably delicate ; it is of no use as a colour, 
 as it is instantly decomposed when heated. To prepare iodide of 
 ethyl, ordinary alcohol is treated with iodine and phosphorus ; 
 
26 THE BRITISH COAL-TAR INDUSTRY 
 
 , the operation has to be conducted with care, as iodine reacts 
 upon phosphorus with great energy ; usually the alcohol and 
 phosphorus are placed in a retort, and the iodine added very 
 carefully, and in small quantities at the time. The mixture is 
 then distilled, and the distillate mixed with water, which causes 
 the iodide of ethyl to separate as a colourless heavy oil. Iodide 
 of ethyl is very volatile, boiling at 70 C. ; it has an ethereal 
 odour, and when pure is colourless and transparent ; it contains 
 no less than 81 per cent, of iodine. Iodide of methyl is 
 prepared in exactly the same manner as that of ethyl, substituting 
 wood naphtha, or methylic alcohol, for ordinary alcohol ; it 
 contains a still larger quantity of iodine than the iodide of ethyl, 
 viz. 89 per cent. 
 
 For the preparation of these substances on the large scale 
 special apparatus has been devised, and sometimes amorphous or 
 red phosphorus is substituted for the ordinary kind ; but I shall 
 not have time to enter more fully into this subject. To produce 
 the violets, Dr Hofmann heats pure rosaniline with iodide of 
 ethyl, or methyl and methylated spirits of wine, in a cast-iron 
 digester, closed airtight, with a lid fastened down with screws. 
 A process very similar to this is sometimes employed, and 
 consists in using a salt of rosaniline, caustic alkali, iodide of 
 ethyl, and alcohol. But in Germany the ordinary hydrochlorate 
 of rosaniline is employed with alcohol, or wood spirit and iodide 
 of ethyl, and is found to work very successfully. By employing 
 the rosaniline itself a lower temperature is required for the 
 formation of violet than when using its salts ; in fact, I have 
 found that a mixture of iodide of ethyl and rosaniline reacts 
 even at the ordinary temperature if left in contact for a few days, 
 and produces a red shade of violet. 
 
 On the large scale Hofmann's violet is generally prepared 
 in deep cast-iron vessels, surrounded by a steam jacket, and 
 provided with a lid having a perforation, closed with a screw 
 plug. This lid can be firmly fastened down with screws, the 
 joint being made with a vulcanised indiarubber washer. This 
 apparatus is charged with a mixture of hydrochlorate of rosaniline 
 dissolved in alcohol or wood spirit, and iodide of ethyl or methyl, 
 in proportion according to the shade required. After the 
 apparatus is closed the steam is allowed to enter the steam jacket, 
 and the heating continued for five or six hours ; the plug is then 
 removed from the lid of the apparatus, and the alcohol or unused 
 
THE ANILINE OR COAL-TAR COLOURS 27 
 
 iodide of ethyl distilled off. The resulting product is dissolved 
 in water, filtered, and precipitated with chloride of sodium, but 
 sometimes it is first treated with caustic alkali, to remove all the 
 iodine, so that it may be recovered. Thus obtained, the colour- 
 ing matter is of a golden lustre if of a blue shade, and of a 
 greenish lustre if of a red shade. 
 
 Like all the other colours we have considered, the Hofmann 
 violets are nearly white organic bases, their composition differing 
 according to the shade of colour, thus : 
 
 A red shade is composed of . . . C 22 H 2S N 3 
 A red-violet shade, of .... C 24 H 27 N 3 
 A very blue shade C 26 H 31 N 8 
 
 The colours of the Hofmann violets are remarkable for their 
 brilliancy, but, unfortunately, they do not resist the action of 
 light so well as* might be desired ; it is remarkable, however, 
 that the regard for fastness seems to have given way to the 
 desire for brilliancy. 
 
 In the early days of coal-tar colours fastness was so much 
 talked about, that when magenta was first introduced it was 
 thought by some that it would not be largely used how 
 different has it proved to be ! Although not very fast upon 
 cotton, the Hofmann violets are sufficiently so for woollen and 
 silk goods, as colours always resist the light better when applied 
 to animal fibres. 
 
 In the formation of Hofmann violets we see that rosaniline, 
 when treated with iodide of ethyl, becomes blue, the red being 
 converted into violet ; but with mauveine, the base of the mauve, 
 exactly the reverse takes place, the mauveine being converted 
 into a much redder shade with iodide of ethyl. The colouring 
 matter produced from mauveine and iodide of ethyl is com- 
 mercially known as " dahlia " ; the colour is intermediate in shade 
 between aniline purple and magenta. The colouring matter 
 possesses the same character for fastness as the mauve, and also 
 gives the same reactions with acids ; unfortunately, it is rather 
 expensive, and has therefore not been very extensively used. 
 
 Lastly, there has been a process proposed for the production 
 of colouring matters similar to the Hofmann violets, by first 
 converting the aniline into ethyl-aniline, a base previously dis- 
 covered by Dr Hofmann. It is found that by substituting this 
 base for aniline, in some of the processes which have been em- 
 
28 THE BRITISH COAL-TAR INDUSTRY 
 
 ployed for the manufacture of magenta, the ethyl-aniline yields 
 purple or violet colouring matters. 
 
 This process has been patented by MM. Poirrier and Chappat, 
 but the reaction appears to have been first observed by M. E. 
 Kopp. From the great similarity of these colouring matters 
 to the Hofmann violets, I need not enter into any lengthened 
 description of their properties. 
 
 Sea-water contains, besides iodine, another remarkable 
 element called bromine ; it is a liquid giving off very irritating 
 orange-coloured vapours. This remarkable body yields, with 
 many hydrocarbons, a great variety of compounds. With 
 ordinary turpentine, it acts with great violence ; but if the action 
 be moderated by the presence of a large quantity of water, a 
 thick viscid oil is obtained. This body was examined by Mr 
 C. Greville Williams, who found it to possess the formula 
 
 I have found that this substance, when heated with a solution 
 of magenta in methylated spirits, produces a purple colouring 
 matter of great beauty, commonly known as Britannia violet ; 
 it is very extensively employed for dyeing and printing, and can 
 be produced of any shade, from purple to a blue violet. 
 
 The Britannia violet possesses the golden-green lustre so 
 common to all the aniline colours. It is easily fusible, amorph- 
 ous, and very soluble in water. 
 
 Earlier in my lecture I showed you the great intensity of the 
 mauve dye. I will now make a few experiments, to illustrate 
 the great intensity of some of the colouring matters we have 
 been considering this evening. 
 
 I have here some screens of white paper, on which I have 
 dusted a very small quantity of the solid colouring matters 
 so small a quantity that I daresay you can scarcely discover its 
 presence. If I now project spirits of wine upon these screens, 
 so as to dissolve the colours, you will see their remarkable 
 intensity. 
 
 Let us now consider for a moment the great rapidity with 
 which the discovery of new coal-tar colours followed that of the 
 mauve or aniline purple. 
 
 Aniline purple was discovered in 1856 ; three years after- 
 wards, in 1859, the magenta was introduced. In 1861 we had 
 the aniline blue; in 1863 the Hofmann violet; and in 1865 
 
THE ANILINE OR COAL-TAR COLOURS 29 
 
 the Britannia violet. Thus we see that all these colours have 
 not only been discovered, but introduced commercially, in a 
 period of less than ten years. 
 
 We have now reviewed the principal coal-tar colours, but 
 there still remain some important ones for our consideration ; 
 and although some of these are not at present largely used, 
 yet it is to them, perhaps, that we may look for the future 
 development of this branch of industry. 
 
 Ill 
 
 VARIOUS ANILINE, PHENOL, AND NAPHTHALINE COLOURS 
 APPLICATION OF THE COAL-TAR COLOURS TO THE ARTS 
 
 The first green colouring matter to consider is the " aldehyd 
 
 freen," which owes its name to a substance called "aldehyd" 
 eing employed in its preparation. I must, therefore, first tell 
 you what aldehyd is. 
 
 Aldehyd is a product of the oxidation of alcohol ; it is a 
 volatile liquid possessing a very peculiar odour, and was dis- 
 covered by a chemist named Dobereiner, but analysed by Liebig. 
 It is obtained by treating alcohol with a mixture of bichromate 
 of potassium and sulphuric .acid, and was generally prepared in 
 glass retorts, but, now that it is required for colour making, the 
 glass apparatus is replaced by copper or leaden vessels. 
 
 Towards the end of 1861, M. Lauth described a reaction by 
 which rosaniline could be made to produce a blue colouring 
 matter ; but this product was found to be useless as a dye, on 
 account of its instability. It was produced by the action of 
 aldehyd upon a solution of rosaniline and sulphuric acid. This 
 useless colour was afterwards experimented upon by a dyer 
 named Cherpin, who, after a number of fruitless attempts at 
 fixing it, told his difficulties to a photographic friend, who evi- 
 dently thought if it was possible to fix a photograph it was possible 
 to fix anything else. He, therefore, advised his confidant to try 
 hyposulphite of sodium. On making i-this experiment, however, 
 the dyer did not succeed in fixing his blue, but found it converted 
 into a splendid green dye, now known as aldehyd green. 
 
 To prepare this colouring matter, a cold solution of magenta, 
 consisting of one part of colouring matter dissolved in a mixture 
 of three parts of sulphuric acid and one part of water, is em- 
 
30 THE BRITISH COAL-TAR INDUSTRY 
 
 ployed ; about one and a half parts of aldehyd are added by 
 degrees to this solution, and when the whole is mixed it is heated 
 on a water bath, until a drop of the product diffused in water 
 produces a fine blue coloration. It is then poured into a 
 large quantity of boiling water, containing three or four times as 
 much hyposulphite of sodium as the magenta employed. After 
 boiling a short time the product is filtered off from a greyish 
 insoluble residue which forms. The filtrate contains the green. 
 This process being a very simple one, a great number of dyers 
 now prepare the colouring matter as they require it. It may, 
 however, be precipitated by means of tannin or acetate of sodium, 
 collected on filters and drained to a paste, and, if necessary, dried. 
 In both these forms it is found in the market. 
 
 The aldehyd green is principally employed in silk dyeing. It 
 is a splendid colour, and very brilliant both by day and artificial 
 light. The chemistry of this green is at present hidden in 
 obscurity, as it is very difficult to obtain in a chemically pure 
 condition. But, like the colouring matter previously described, 
 it is undoubtedly the salt of an organic base apparently containing 
 sulphur. 
 
 This base is colourless, or nearly so, and becomes changed 
 to the normal colour of aldehyd green upon the absorption of 
 carbonic acid. 
 
 It will also decompose ammonia salts, combining with the 
 acid and becoming green. I have here a solution containing the 
 colourless base of this green, an ammonia salt and a little free 
 ammonia. If I pour it upon a piece of white blotting-paper it 
 does not stain it, but if I heat it the ammonia salt is decomposed, 
 and we get the green developed with its ordinary intensity. 
 
 There is another green of an entirely different nature to 
 the aldehyd green ; it is called iodine green. This colouring 
 matter is always produced, but in variable quantities, in the 
 preparation of the Hofmann violets, from magenta and iodide of 
 ethyl or methyl. Of late much attention has been directed to 
 this colouring matter, and, by making a few alterations in the 
 process for preparing Hofmann violet, from forty to fifty per 
 cent, of product can now be obtained from the magenta used. 
 The iodine green is much used for cotton and silk dyeing ; its 
 colour is bluer than that of aldehyd green, and it is, therefore, 
 more useful, as it yields, with the addition of yellow, a greater 
 variety of green shades. 
 
THE ANILINE OR COAL-TAR COLOURS 31 
 
 Iodine green contains an organic base which is not precipitated 
 by alkaline carbonates. With picric acid it forms a difficultly 
 soluble picrate, and is generally prepared on the Continent as a 
 paste consisting of this colour precipitated with picric acid and 
 drained on a filter. In England it is, however, sold in alcoholic 
 solution. It is a good green by gaslight. 
 
 The next green I have to bring before you is a magenta deri- 
 vative, commercially called " Perkin's green." In its properties 
 it resembles more closely the iodine than the aldehyd green, but 
 differs from this in its solubility, and in being precipitated by 
 solutions of alkaline carbonates, such as carbonate of sodium. It 
 is an organic base which is nearly colourless, and is by no means 
 a chemically powerful body. Like the iodine green, it is precipi- 
 tated by picric acid, forming a picrate which crystallises from 
 alcohol in small prisms with a golden reflection. This colouring 
 matter is principally employed for calico printing, and is now 
 extensively used. Thus you see we have three aniline greens, 
 some useful for one, and some for another purpose, so that the 
 silk and cotton dyer and the calico-printer, as well as others, can 
 be supplied. For fastness these greens are, I think, quite as 
 good as the violets ; the aldehyd green, however, I believe, 
 resists light the best. 
 
 In the formation of the mauve, or aniline purple, there is 
 always a small quantity of a second colouring matter produced, 
 of a rich crimson colour, similar to that of safflower. Several 
 years ago I examined this substance, and found it to dye silk 
 a remarkably clear colour, but owing to the press of other 
 matters, and the very small quantities in which it could be 
 obtained, 1 did not give it any further attention. By a new 
 process, however, it can now be produced in somewhat larger 
 quantities, and endeavours are being made to introduce it to the 
 arts, as it produces beautiful tints of pink upon silk and cotton, 
 and, moreover, can be used for printing cotton, silk, and wool 
 processes, to which safflower cannot be applied as it will not 
 bear steaming. This aniline pink or crimson is a beautiful 
 chemical body, crystallising in small prisms possessing a golden- 
 green lustre. It is soluble in alcohol, and also in water ; it 
 produces solutions remarkable for their fluorescence so much 
 so, that by certain lights they appear as if filled with a precipitate. 
 In colour and fastness it is equal to safflower, and, should it be 
 found possible to manufacture it at a moderate price, I should 
 
32 THE BRITISH COAL-TAR INDUSTRY 
 
 imagine it would entirely supersede that colouring matter, 
 especially as it is not affected by alkaline solutions. 
 
 There is a product in the English market, supposed to be an 
 aniline colour, called " Field's orange," after its discoverer, Mr 
 Frederick Field. Its properties are those of a nitro-acid, but, as 
 its preparation has not been described, of course I cannot tell 
 you anything about it. With alkalies it forms a rich orange- 
 coloured solution, but by the addition of an acid it is precipitated 
 as a pale yellow powder. 
 
 Field's orange is a very useful colouring matter, having a 
 great affinity for animal fibres, and is extensively used for wool- 
 dyeing, as it resists the action of light very well. 
 
 We now come to a colouring matter of a very indefinite 
 nature. I refer to aniline black. This substance appears to be 
 closely allied to the insoluble part of the black precipitate formed 
 in the manufacture of the mauve. This precipitate, however, 
 always contains oxide of chromium, which cannot exist in the 
 aniline black generally employed, as no chromium compound is 
 used in its preparation ; but as copper compounds are used, it 
 may be that aniline black represents the black precipitate with 
 the oxide of chromium replaced by the oxide of copper, or it 
 may even be that in either case the metallic oxide is not an 
 essential part of this black substance. 
 
 Aniline black is perfectly insoluble, and has, therefore, to be 
 formed upon the fibre when employed for calico-printing. As 
 we shall have to refer to its application to dyeing and printing, I 
 will not make any further remarks upon it just now. 
 
 From mauve and magenta, chocolate, maroons and browns are 
 prepared ; but as they are of secondary importance as yet, I will 
 only just mention one or two of the methods of preparing them. 
 
 One of the processes for preparing chocolate from magenta is 
 by the action of nitrous acid, but care has to be taken to watch 
 the progress of the operation, and to stop it when the required 
 shade has been obtained. Another process consists in heating 
 magenta with hydrochlorate of aniline to a temperature a little 
 above 200 C. The product, when purified, produces a maroon 
 colour. Browns are generally obtained from a residue of 
 magenta making. 
 
 All the colouring matters we have considered up to the 
 present time are derivatives of aniline and toluidine, and con- 
 stitute nearly all the colours of the rainbow. 
 
THE ANILINE OR COAL-TAR COLOURS 33 
 
 By the action of nascent hydrogen upon dinitrobenzol, Mr 
 A. H. Church and myself obtained, in 1857, a crimson colouring 
 matter, which was named nitrosophenyline. I have lately made 
 a few new experiments upon this remarkable body, and find that 
 it has an affinity for pure cotton, dyeing it of a clear cerise colour, 
 considerably less blue in tint than safflower. With very dilute 
 acids, this colouring matter forms a blue solution ; with less 
 dilute acid, a crimson colour ; and with concentrated sulphuric 
 acid, a green colour. It is difficult to judge of the probable 
 utility of this colouring matter, as it is so difficult to obtain in 
 quantity by the present process. I may mention that my new 
 experiments with this substance have caused me to doubt the 
 purity of the product examined by Mr Church and myself ; and 
 this is not remarkable when we consider how few methods of 
 purifying artificial colouring matters were known at the date of 
 our experiments, as well as the small amount of substances at 
 our disposal. 
 
 We now turn to a product very different from aniline, though 
 related to it in some respects very closely. On the table you 
 will see a coal-tar product called " phenol " or " carbolic acid." 
 It was discovered, a long time since, by Runge, and afterwards 
 studied by a great number of chemists. It is only, however, 
 during the last few years that it has been introduced into com- 
 merce in a pure condition, thanks to Dr Crace Calvert. 
 
 Phenol or carbolic acid is a splendid crystalline body, pos- 
 sessing many most interesting properties ; but I must confine 
 myself to a short account of its coloured derivatives only. 
 
 Carbolic acid, when treated with nitric acid, yields a yellow 
 acid, known as picric acid. The substance can be produced from 
 many other bodies besides carbolic acid, and when first employed 
 for dyeing purposes was generally prepared from the resin of 
 the Xanthorrhea hastilis, but now, owing to the cheapness and 
 purity of carbolic acid, I believe it is exclusively used in its 
 manufacture. Picric acid requires care in its preparation, if 
 phenol and strong nitric acid be employed, as the action is very 
 violent. Pure picric acid is of a very pale yellow colour ; it is 
 employed principally for silk-dyeing, the colour it produces on 
 silk being much darker than that of the acid itself. Picric acid 
 has a very bitter taste, and by some it is said to be a great 
 improvement upon hops in the manufacture of bitter beer, 
 especially as it has been proposed as a tonic in place of quinine. 
 
 3 
 
34 THE BRITISH COAL-TAR INDUSTRY 
 
 Picric acid forms beautiful yellow salts, the most interesting 
 being that of potassium. This salt is extremely insoluble in 
 water, and very explosive ; it has been proposed as a substitute 
 for gunpowder for charging shells. Picric acid, under the 
 influence of cyanide of potassium, is perfectly decomposed, and 
 changed into a new compound called isopurpuric acid, a substance 
 isomeric with murexide. The potassium salt of this compound 
 is very explosive, and, to avoid danger, it is generally supplied 
 in a moist condition, and mixed with glycerine. It produces a 
 kind of maroon colour upon wool, but I do not think it has 
 been extensively used up to the present. 
 
 Runge, when experimenting with the products of the dis- 
 tillation of coal, obtained two compounds, called by him rosolic 
 and brunolic acids, which he regarded as products existing in 
 coal tar ; I think it most probable, however, that these bodies 
 were produced in his process of purification, and did not exist 
 ready formed in coal tar. 
 
 Rosolic acid was afterwards examined by Dr Hugo Mailer, 
 who obtained it from crude carbolate of calcium, which had 
 been exposed to the oxidising action of the air. This process, 
 however, does not yield rosolic acid in quantity ; but in 1861, 
 Kolbe and Schmitt described a method of producing this sub- 
 stance, by heating a mixture of oxalic, carbolic, and sulphuric 
 acids. It is stated, however, that this process was discovered 
 by M. Jules Persoz, in 1859. ^ ls by this method that rosolic 
 acid is now manufactured. 
 
 Commercial rosolic acid, commonly called aurine, is a 
 beautiful brittle resinous substance, having a slight green metallic 
 lustre ; when pure it may be crystallised, and if pulverised forms 
 a scarlet orange powder. Its solutions are of an orange colour, 
 but change with alkalies to a most magnificent crimson. It 
 has not been found capable of very many applications in dyeing 
 and printing, although it produces very good orange shades, 
 and with magenta it makes a very good scarlet. 
 
 The great difficulty in applying rosolic acid to the arts is 
 owing to the easy solubility of its salts in water. It appears to 
 be closely allied to rosaniline, as it has lately been found possible 
 to obtain it from this colouring matter. 
 
 When heated with ammonia, in a closed vessel, to 120 to 
 140 C., rosolic acid permanently changes into a new colouring 
 matter of a crimson shade, called peonine or coralline. This 
 
THE ANILINE OR COAL-TAR COLOURS 35 
 
 forms beautiful tints upon silk, similar to safflower, provided 
 it is kept slightly alkaline, but if treated with the least quantity 
 of acid the freshness of its colour is destroyed. When heated 
 with aniline this colouring matter undergoes a similar change 
 to magenta, being converted into a blue called azuline. This 
 colouring matter, as well as coralline, was discovered by M. Jules 
 Persoz, and patented by MM. Guinon Mamas & Bonnet in 1862. 
 Azuline, when in the solid state, presents a coppery-coloured sur- 
 face ; it is soluble in alcohol, but difficultly so in water. It is not 
 manufactured now, having been replaced by the more brilliant 
 blues obtained from rosaniline, and described previously. 
 
 We must now turn our attention to another series of coal- 
 tar colours, derived from a beautiful product called naphthaline. 
 You will see it on the table of coal-tar products ; it is a hydro- 
 carbon containing 
 
 CioH 8 
 
 and may be obtained in any quantity. It is remarkable for the 
 readiness with which it sublimes, and, like benzol and toluol, 
 it yields with nitric acid a nitro-compound called cc nitronaphtha- 
 line," a beautifully crystalline body, and this, with iron and acetic 
 acid, yields an organic base called " naphthylamine." This base 
 is solid, and beautifully crystalline, but possesses a very dis- 
 agreeable odour. 
 
 Mr Church and myself obtained from a salt of " naphthyl- 
 amine " and a mixture of nitrate of potassium and potash, a 
 beautiful substance crystallising in orange needles with a green 
 lustre. It is called by a rather long name, " azodinaphthyldiamine." 
 
 This substance is a feeble organic base, and dissolves in 
 alcohol, forming an orange-coloured solution, which changes 
 to a splendid violet colour upon the addition of hydrochloric 
 acid. It has, however, been found useless as a dye, because 
 the purple colour only exists in the presence of free acid, and 
 the orange colour of the base itself is liable to turn brown when 
 exposed to the light. It would appear probable, however, that 
 azodinaphthyldiamine may become useful as the starting-point for 
 new colouring matters, as I have lately succeeded in producing 
 from it a very promising crimson substance, possessing a con- 
 siderable affinity for animal fibres. 
 
 A very beautiful yellow colouring matter has been obtained 
 by Dr Martius from naphthylamine, somewhat similar to picric 
 acid, but of a much more intense colour. It is prepared by 
 
36 THE BRITISH COAL-TAR INDUSTRY 
 
 treating hydrochlorate of naphthylamine with nitrite of potassium ; 
 by this means a substance known as diazonaphthol is obtained ; 
 this is then heated with nitric acid, and is transformed into the 
 new yellow, chemically known as dinitronaphthol. This sub- 
 stance is commercially called Manchester yellow. It possesses 
 the properties of an acid. The commercial compound consists 
 of a beautifully crystalline calcium salt, soluble in water, and 
 dyeing silk or wool a magnificent golden-yellow colour. 
 
 Owing to an increasing demand for benzoic acid, experiments 
 have lately been made with a view of obtaining it from naphthal- 
 ine instead of gum benzoin, etc. For this purpose experiments 
 were made with an acid derived from naphthaline, called phthalic 
 acid, which, when carefully heated with lime, is found capable of 
 yielding benzoate of calcium, from which benzoic acid can be 
 prepared. But as in these processes secondary compounds are 
 formed, which interest us this evening, I will briefly describe the 
 process employed for obtaining these various substances. 
 
 First of all, naphthaline is heated with a mixture of chlorate 
 of potassium and hydrochloric acid ; in this way a mixture of 
 chloronaphthaline and bichloronaphthaline is obtained. These 
 products are then heated with nitric acid, and yield a mixture of 
 phthalic acid and a substance called the chloride of chloroxy- 
 naphthyl. The phthalic acid is converted into the calcium salt, 
 and heated with slaked lime to a temperature of 350 or 370 C., 
 to convert it into a benzoate. 
 
 It is, however, the chloride of chloroxynaphthyl which 
 interests us now. This substance, when heated with an alkali, 
 yields the salts of an acid called chloroxynaphthalic acid, which 
 may be obtained in a free state by means of hydrochloric acid. 
 When pure, chloroxynaphthalic acid is a pale yellow crystalline 
 powder, forming beautiful compounds with baryta, zinc, and 
 copper. It dyes wool a scarlet colour. The great interest of 
 this substance consists in its supposed relationship to alizarine, 
 the colouring matter of madder, the only difference in composition 
 of chloroxynaphthalic acid and alizarine being in the former 
 containing an equivalent of chlorine in place of hydrogen, thus : 
 
 C 10 H 6 O 3 . . . Alizarine. 
 
 C 10 (H 5 C1)O 8 . . . Chloroxynaphthalic acid. 
 
 Many endeavours have been made to remove this chlorine, 
 and to put hydrogen in its place, with the hopes of producing 
 
THE ANILINE OR COAL-TAR COLOURS 37 
 
 alizarine ; but, up to the present time, no definite results have 
 been obtained. 
 
 I am inclined to think that, although this relationship 
 of composition exists between these bodies, yet that their 
 chemical nature is quite dissimilar. We generally find that 
 chlorinated bodies have similar properties to those from which 
 they are derived or represent. Chloroxynaphthalic acid, 
 however, does not appear to possess properties similar to 
 alizarine. This acid dyes wool readily without a mordant ; 
 alizarine only slightly stains it. When boiled with cloth prepared 
 with alumina, or iron mordants, it scarcely produces any change, 
 while alizarine yields intense colours. 
 
 This process of preparing benzoic and chloroxynaphthalic 
 acids is carried out on a large scale in France, by MM. P. & 
 E. Depouilly, to whom I am indebted for the specimens of these 
 products shown in this lecture. Some of the chloroxynaphthalates 
 are beautifully coloured salts, and are used as pigments. 
 
 Laurent in his researches obtained a body from naphthaline 
 called carminaphtha. This product is now claiming the attention 
 of manufacturers, and is said to produce very fine shades of 
 colour upon fabrics. 
 
 Before making any further remarks upon the coal-tar colours, 
 I wish to draw your attention to some of their applications to 
 the arts. 
 
 I have told you that most of the coal-tar colours contain 
 carbon, hydrogen, and nitrogen, and that they are generally 
 organic bases. They differ essentially from most of the vegetable 
 colouring matters, which contain, with but few exceptions, only 
 carbon, hydrogen, and oxygen, and are weak acids. You will 
 thus understand that many difficulties had to be encountered in 
 their application for dyeing and printing, because they would not 
 combine with the ordinary mordants used for the colouring 
 matters of woods, such as alumina and oxide of tin. These 
 observations refer to the dyeing and printing of vegetable fibres, 
 and not to silk or wool, as these materials absorb the coal-tar 
 colours without the intervention of a mordant. 
 
 In silk-dyeing, the principal difficulty experienced in applying 
 the coal-tar colours was due to their great affinity for the fibre, 
 thus preventing the dyer from obtaining an even colour, especially 
 when dyeing light shades. After a time, however, it was found 
 that this obstacle could be overcome by dyeing the silk in a weak 
 
38 THE BRITISH COAL-TAR INDUSTRY 
 
 soap lather, to which the colour had been added. This not only 
 caused the dyeing to proceed with less rapidity, but also kept the 
 surface of the silk in good condition. Silk dyed by this process 
 is left soft, but may afterwards be rendered hard or " scroop " by 
 rinsing in a bath of slightly acidulated water. 
 
 This process was first used for dyeing silk with the mauve 
 or aniline purple. It has, however, been since found suitable for 
 nearly all the aniline colours, such as magenta, Hofmann and 
 Britannia violets, etc. For dyeing silk with coal-tar colours of 
 an acid nature, such as picric acid, dinitronaphthol, etc., the silk 
 is simply worked in a cold aqueous solution of the colouring 
 matter, sometimes slightly acidulated, as when using the sulpho 
 acids of aniline blue or soluble blue. The process of printing 
 silk with aniline colours is comparatively simple. An aqueous 
 or alcoholic solution of the colouring matter is thickened with 
 gum Senegal, printed on with blocks, and, when dry, exposed to 
 the action of steam for about half an hour. The gum is then 
 washed off, and the goods finished. 
 
 Earlier in my lecture I referred to the formation of two 
 colourless products from magenta, the one called leucaniline, 
 and the other hydrocyanrosaniline. 
 
 Some few years since, it was found that if silk dyed with 
 magenta has the reagents necessary for the formation of these 
 colourless products printed upon it, what is called a discharge 
 style can be produced. One of the substances used for effecting 
 this change is powdered zinc mixed with gum. This process 
 also applies to all the coloured derivatives of magenta, and yields 
 better results than can be obtained by printing on the colouring 
 matter and leaving the white parts, because the colours are 
 always clearer when dyed than when printed. But this is not all. 
 When printing two colours on silk, say a pattern with a green 
 ground and purple spots, two blocks have to be used, the one 
 for the ground and the other for the spots ; and, when re- 
 moving the first block, the silk often moves slightly, therefore 
 when the spots are put in by the second block they do not 
 exactly register, and thus an imperfect result is obtained. 
 This difficulty, however, can be avoided by taking silk dyed 
 with any of the derivatives of magenta, and printing it with 
 the discharge previously mixed with the colour it is desired 
 to introduce, of course employing a colouring matter which is 
 not affected by the discharge, such as aniline purple, aniline 
 
THE ANILINE OR COAL-TAR COLOURS 39 
 
 pink, etc. This discharge style has only been employed for silk 
 at present. 
 
 We will now turn our attention to the methods of dyeing 
 wool. These methods, as a rule, are very simple, the wool being 
 merely worked in a hot aqueous solution of the desired colouring 
 matter, no mordant being required. Acids are generally found 
 to be injurious, a neutral bath being preferred, and the operation 
 finished by bringing the temperature nearly up to that of boiling 
 water. 
 
 With the blue known as Nicholson's blue, the process of 
 dyeing is different from that just given, and consists of two 
 distinct operations, the wool being first worked in an alkaline 
 solution of the colour, which gives it a kind of grey or slate 
 shade, and then in an acid bath, which develops the colour. 
 
 The printing of wool is similar to that of silk, the colouring 
 matter being simply thickened with gum, printed on the goods, 
 steamed, and then washed. 
 
 The dyeing of cotton with aniline purple at first presented 
 many difficulties. This colouring matter was found to be capable 
 of producing a very beautiful colour without a mordant, and it 
 was proposed to employ it in this manner, but the colour thus 
 obtained would not bear washing, being nearly all removed with 
 hot water and soap. Mordants, such as alum, were then ex- 
 perimented with, but these gave no results. After some time 
 Mr R. Pullar and myself found a method of applying this 
 colouring matter to cotton, which is based upon the insolubility 
 of the compounds it forms with tannin. In using this process 
 the cotton is first soaked in a decoction of sumac or some 
 other tannin agent, then in a solution of stannate of soda, and, 
 lastly, in water slightly acidulated with sulphuric acid. The 
 cotton thus prepared contains an insoluble compound of tin and 
 tannin, which possesses a great affinity for aniline purple. The 
 stannate of soda may be replaced by alum, or a solution of tin 
 salt. This method of preparing cotton has been found suitable 
 for nearly all the aniline colours discovered since the mauve, and 
 is now almost universally employed in Great Britain for cotton- 
 dyeing. Other processes have been proposed for cotton-dyeing, 
 but are not so generally employed as the one just described. 
 
 We now pass on to the application of coal-tar colours to the 
 art of calico-printing. The mauve, when first introduced, was 
 applied to printing in a very simple manner ; the colouring 
 
40 THE BRITISH COAL-TAR INDUSTRY 
 
 matter was merely mixed with gum and albumen, printed on the 
 goods and steamed ; by this process the albumen became in- 
 soluble, and fixed the colour. Caseine and gluten were some- 
 times used as substitutes for albumen. Being dissatisfied with 
 this mechanical mode of applying aniline purple, in conjunction 
 with Mr Grey I made a number of experiments with a view of 
 obtaining some more chemical method of fixing this colouring 
 matter, and at last succeeded. The process proposed consisted 
 in printing the pattern with a salt of lead, then converting this 
 into the oxide or a basic salt, by passing the goods through an 
 alkaline solution. Thus prepared, they were worked in a boiling 
 solution of aniline purple in soap. In this way a very pure 
 colour was obtained on the mordanted parts, the soap keeping 
 the whites pure. This process, however, was of very limited 
 application, as it could only be applied for single-colour patterns. 
 After this, several processes were patented for the use of tannin 
 for fixing the mauve ; these were based upon the method of 
 dyeing cotton previously mentioned, and some very fast results 
 were obtained ; but as these methods are now out of use, I will 
 not describe them further. 
 
 The process now nearly universally employed in the north 
 was discovered by M. Alexander Schultz and myself ; it consists 
 in printing the colouring matter with a mordant composed of 
 a solution of arsenite of alumina in acetate of alumina. On 
 steaming the cloth printed with this mixture for about half an 
 hour, the colour is firmly fixed in the fibre. After steaming, 
 the goods are generally soaped, and then finished. One of the 
 great advantages of this process is that it can be worked in 
 patterns with a great variety of colours, and is also suitable for 
 nearly all the aniline colours, as well as the mauve, yielding 
 shades of great brilliancy. 
 
 During the last few years, much attention has been given 
 to the application of aniline black in calico-printing. This 
 substance is not prepared in the separate condition, but formed 
 on the fabric ; it is produced by printing a mixture of a salt of 
 aniline, chlorate of potassium, and sulphide of copper, thickened 
 with starch, upon the goods, and in this manner a dull grey 
 impression is obtained ; but, after three or four days' ageing, 
 this changes to a dark olive, and is then rendered perfectly black 
 by passing the goods through a dilute solution of carbonate 
 of soda. This colour is very fast, but is inclined to acquire a 
 
THE ANILINE OR COAL-TAR COLOURS 41 
 
 slightly green shade by long exposure to the air. Unfortunately, 
 it cannot be printed on with other colours, because when steamed 
 the cotton is destroyed by the acid character of the mixture 
 employed for its formation. It can, however, be printed on at 
 the same time as madder mordants, and these can be afterwards 
 dyed with a lead mordant, so that when passed through bi- 
 chromate of potassium a pattern with black and yellow or orange 
 can be obtained. 
 
 The aniline colours have produced quite a revolution in the 
 arts of dyeing and printing, and have made these processes far 
 simpler than they were, and there is such a variety of shades of 
 colour now sent into the market that the dyer or printer has 
 little else to consider than the intensity of the colour required ; 
 and, in fact, if a dyer has a large order to execute of a particular 
 shade of colour not in the market, he will not trouble about 
 matching it himself, but sends to the colour manufacturer to 
 supply him with a product capable of yielding the required shade. 
 
 Besides dyeing and calico-printing, several other branches 
 of industry have benefited by the coal-tar colours, such as the 
 arts of lithography, type-printing, paper staining and colouring, 
 etc. Before they could, however, be used for these various 
 purposes, it was necessary that they should be made into lakes 
 or pigments, by union with alumina or other suitable base ; but 
 as most of the aniline colours are of a basic nature, it was found 
 impossible to combine them directly with a metallic oxide like 
 alumina ; advantage was, therefore, taken of their affinity for 
 starch granules, and some very brilliant products were obtained 
 by dyeing powdered starch with the cold aqueous solution of 
 these colouring matters. These starch powders, however, are 
 wanting in covering power or body, so that other processes had 
 to be sought for, and now these lakes are made upon an alumina 
 base, by the intervention of tannin or benzoic acid. 
 
 Many attempts have been made to prepare a pigment from 
 rosolic acid or aurine, and this, to some extent, has been accom- 
 plished by precipitating a solution of the colouring matter with 
 alumina ; by this process, a bright orange-scarlet-coloured pro- 
 duct can be obtained ; it is, however, only suitable for paper- 
 staining. I have, therefore, lately been further experimenting 
 in this direction, and have succeeded in forming a very brilliant 
 scarlet pigment, which can be used for printing-inks and a 
 variety of other purposes. 
 
42 THE BRITISH COAL-TAR INDUSTRY 
 
 Upon the table there are some specimens of magenta, 
 Britannia violet, aniline blue, green and orange lakes, and also 
 some very beautiful and intense-coloured preparations of coal- 
 tar colours, now generally called carmines. These lakes, when 
 ground with printers' varnish, produce printing-inks of very 
 great brilliancy, and are extensively used for this purpose ; and 
 Mr Hanhart, whose name is so intimately connected with the 
 art of lithography, has most kindly furnished me with the various 
 illustrations of the application of these products to lithographic 
 printing for this lecture. 
 
 These lakes in a wet condition are being largely used for 
 paper-staining, and also for paper-colouring, as well as for a 
 variety of other less important purposes. 
 
 The peculiar bronze surface produced by evaporating a 
 solution of an aniline colour has been taken advantage of by the 
 manufacturer ; and all the bronze bonnets, hats, flowers, and 
 feathers, so much worn in the autumn of last year, derived their 
 lustre from aniline colours. When first employed for this 
 purpose, no fixing agent was used with them ; and as they are 
 mostly soluble in water, a shower of rain was often found to 
 cause beautiful purple drops to fall from these bronzed bonnets 
 and hats, and produce a kind of mottled pattern upon the white 
 collars, and sometimes even upon the face, of the wearer. 
 
 Aniline colours are used for writing-inks, colouring soap, 
 etc. ; but as these applications are only of small importance from 
 a commercial point of view, I will not spend time in speaking 
 about them. 
 
 I have in this lecture brought before you in a rapid I fear 
 too rapid manner an account of most of the coal-tar colours ; 
 but, before concluding, I should like to show you the close 
 relationship which exists between some of them, especially 
 between those derived from rosaniline or magenta. 
 
 I have endeavoured to show you that the derivatives of 
 magenta closely agree in properties, all of them containing 
 colourless organic bases, the colour being developed upon their 
 combining with acids. But I now wish to show you more 
 than this, by briefly explaining their chemical structure. To 
 describe this thoroughly it would be necessary for me to enter 
 fully into the chemical theory of substitution ; but as this would 
 occupy a great deal of time, I must content myself with just 
 mentioning a few facts connected with that subject. 
 
THE ANILINE OR COAL-TAR COLOURS 43 
 
 Rosaniline and its derivatives contain carbon, hydrogen, and 
 nitrogen, as I have told you on a previous occasion. Chemical 
 substances containing hydrogen often hold it in what is termed 
 a replaceable condition, that is, in such a condition that it may 
 easily be removed and another substance of equal value (either 
 simple or compound) introduced in its place. A compound 
 substance, capable of replacing hydrogen, is called a " radical," 
 and I want to speak about two of these radicals, one called ethyl, 
 and contained in iodide of ethyl, the other called phenyl, and 
 contained in aniline. 
 
 Ethyl contains C 2 H 5 . 
 
 Phenyl C 6 H 5 . 
 
 I will first mention a familiar instance of the replacement of 
 hydrogen by a radical. Water is composed of two equivalents 
 of hydrogen and one of oxygen, thus : 
 
 H io 
 
 H/ a 
 
 Now, it is quite easy to remove an equivalent of this hydrogen 
 and replace it by ethyl : 
 
 H 
 
 This is water with hydrogen replaced by ethyl, a replacement 
 compound by some very much preferred to water itself ; it is 
 alcohol. 
 
 Rosaniline contains three equivalents of hydrogen, replace*- 
 able by radicals. This is the formula of the hydrochlorate of 
 rosaniline, the three separate H's being replaceable : 
 
 ( C 20 H 16) 
 
 H 
 
 H 
 
 Now, what takes place upon boiling this salt with aniline ? 
 The phenyl of the aniline simply takes the place of the replaceable 
 hydrogen, producing what is called triphenylrosaniline. The 
 result of this replacement is that the rosaniline salt has been 
 changed from red into blue the bleu de Lyon which is 
 represented thus : 
 
44 THE BRITISH COAL-TAR INDUSTRY 
 
 Dr Hofmann, on observing this relationship, was induced to 
 try whether he could replace the hydrogen in rosaniline by other 
 radicals than phenyl. He tried to introduce ethyl by digesting 
 rosaniline with iodide of ethyl, and succeeded in introducing 
 three molecules of the radical ethyl in the place of the three 
 replaceable hydrogens. I will endeavour to show you how this 
 takes place, by the following equation : 
 
 (C 2 H 5 )I ( C 2oH 16 M HI 
 
 (C 2 H 5 )I + \N y HCl. = HI 
 
 IT ft \ T T-TT 2 5 
 
 (C 2 H 5 )I (C 2 H 5 ) 
 
 Three molecules of Hydrochlorate Three of iodide of Hydrochlorate of 
 
 iodide of ethyl. of rosaniline. hydrogen or triethylrosaniline. 
 
 hydriodic acid. 
 
 Here we see the iodine has simply exchanged its ethyl for 
 the replaceable hydrogen of rosaniline, and the result is a blue 
 shade of the Hofmann violet. 
 
 Now, it is not necessary to replace the three hydrogens ; two 
 may be replaced, and we get a less blue violet. Represented 
 thus : 
 
 H 
 
 Hydrochlorate of 
 diethylrosaniline. 
 
 Or one may be replaced, and we get a red violet. Represented 
 thus : 
 
 (C 2 oH 16 ) 
 
 (C 2 
 
 Hydrochlorate of 
 ethylrosaniline. 
 
 When speaking of the violet imperial, I mentioned that it 
 consisted of products intermediate between rosaniline and the 
 bleu de Lyon. These intermediate substances consist of ros- 
 aniline with one or two equivalents of hydrogen replaced by 
 phenyl. 
 
 Up to the present moment it has only been found possible 
 to replace one equivalent of hydrogen in mauveine, or the mauve 
 dye, and, as I previously mentioned, it is curious that the result 
 
THE ANILINE OR COAL-TAR COLOURS 45 
 
 of this replacement is perfectly opposite to that which takes 
 place in the case of rosaniline, the replacement of hydrogen by 
 ethyl in rosaniline causing it to become bluer in shade, and the 
 replacement of hydrogen by ethyl in mauveine causing it to 
 become redder in shade. The following is the formula of the 
 hydrochlorate of ethyl-mauveine or dahlia : 
 
 But although I have tried to explain the relationship of these 
 colouring matters as simply as I can, yet this part of my lecture 
 assumes much of the character of a lecture on theoretical 
 chemistry. Here we are talking about substitution products 
 of bodies, a branch of the highest theoretical chemistry, and it 
 must strike us as remarkable when we find that these considera- 
 tions have been pressed upon us by the discussion of bodies 
 which may now be said to be common dyestuffs. We have 
 also been talking in quite a familiar manner about nitrobenzol, 
 aniline, iodide of ethyl, aldehyd, etc., substances which were, 
 only a few years since, the recherche compounds of the laboratory. 
 In fact, the coal-tar colour industry is entirely the fruit of theo- 
 retical chemistry. Let us consider the enormous rapidity with 
 which this industry has developed. It only dates from 1856, 
 and now (in 1868) we have large factories for the production 
 of coal-tar colours, not only in Great Britain, but in Germany, 
 France, Switzerland, America, and other countries. I had hoped 
 to have been able to give you a statistical account of this industry, 
 but have not had sufficient time for this purpose. Dr Hofmann, 
 however, in his report on the coal-tar colours shown at the Paris 
 Exhibition of 1867, remarks that "in 1862, the value of these 
 manufactures had risen from nothing to 10,000,000 francs, 
 or more than 400,000 sterling. At the present day this sum 
 is trebled, which would make it about one million and a quarter 
 pounds sterling, although the products are much cheaper than 
 they were before." And, now, when you hear of these results, 
 do not forget that they are the truly practical fruits of theoretical 
 chemistry, not studied for the purpose of producing commercial 
 products, but simply for its own sake. 
 
II. : i8 7 o 
 
 THE ARTIFICIAL PRODUCTION OF 
 ALIZARINE 
 
 BY PROFESSOR H. E. ROSCOE, F.R.S. 
 (Discourse delivered at the Royal Institution, ist April 1870) 
 
 THE discovery of artificial alizarine, whether we regard its 
 scientific interest or its practical and commercial value, is of 
 the highest importance, and marks an era in the history of the 
 application of chemistry to the arts and manufactures even 
 of greater importance than the memorable discovery made by 
 Mr Per kin in 1856 of the production of aniline violet, or 
 mauve. 
 
 Since the above-named year great progress has been made in 
 the theoretical investigation of natural and artificial colouring 
 matters, as well as in their preparation on a large scale. The 
 chemistry of colouring matters has now taken a high and im- 
 portant position, and chemists, instead, as formerly was their 
 wont, of getting rid of all colouring matters as something foreign 
 to their objects of investigation, have, since Mr Perkin's dis- 
 covery, found out that the examination of colouring matters may 
 not only lead to scientific laurels, but may sometimes yield fruit 
 of another and not less acceptable kind. 
 
 We owe to the brains and hands of two German chemists, 
 Graebe and Liebermann, this remarkable discovery, which differs 
 from all the former results which have been brought about by 
 the application of science to the chemistry of colouring matters, 
 inasmuch as this has reference to the artificial production of a 
 natural vegetable colouring substance which has been used as a 
 dye from time immemorial, and is still employed in enormous 
 quantities for the production of the pink, purple, and black 
 
 4 6 
 
THE ARTIFICIAL PRODUCTION OF ALIZARINE 47 
 
 colours which are seen everywhere on printed calicoes, viz. 
 alizarine, the colouring principle of madder. 
 
 It is from the liquid tarry products of the destructive distilla- 
 tion of coal, a rich source of interest to chemists, that we now 
 derive this new colouring matter. 
 
 The following table contains the results of experiments made 
 on a large scale, indicating the various yields of tar from 
 different qualities of coal distilled in the gasworks of various 
 towns : 
 
 DESTRUCTIVE DISTILLATION OF COAL 
 100 tons of cannel and bituminous coal yield the following products: 
 
 
 Gas. 
 
 Tar. 
 
 Ammonia 
 water. 
 
 Coke. 
 
 
 I 
 
 22-25 
 
 8-50 
 
 9'5 
 
 5975 
 
 Average of many 
 
 
 
 
 
 
 experiments. 
 
 2 
 
 20*01 
 
 7-85 
 
 7-14 
 
 65*00 
 
 Manchester. 
 
 1 
 
 2O'4O 
 
 6-4 
 
 5-4 
 
 67-85 
 
 Dukinfield. 
 
 4 
 
 21'7 
 
 7'5 
 
 5'8 
 
 65*0 
 
 Macclesfield. 
 
 5 
 
 I6'3 
 
 10-7 
 
 8-0 
 
 65*0 
 
 Salford. 
 
 From a careful series of experiments made by a large tar 
 distiller the following numbers are derived, showing the average 
 composition of gas tar : 
 
 ioo tons of coal-tar on distillation yield : 
 
 I 
 
 2 
 
 Naphtha. 
 
 Light oils 
 and carbolic 
 acid. 
 
 Heavy oils, 
 naphthalene, 
 anthracene. 
 
 Pitch. 
 
 Water, gas, 
 and loss. 
 
 3*o 
 3' 
 
 i'S 
 
 0-8 
 
 35* 
 25-0 
 
 5o*o 
 60*0 
 
 10-5 
 12*2 
 
 It is from benzol, C 6 H 6 , discovered by Faraday in 1825, that 
 the aniline colours are all of them prepared. The colour-produc- 
 ing powers of the coal products are, however, yet far from being 
 exhausted. It is by means of another and hitherto comparatively 
 unknown hydrocarbon, anthracene, C^Hjo, that the newest 
 
4 8 THE BRITISH COAL-TAR INDUSTRY 
 
 triumphs of the chemist have been won. This is a substance 
 which in the pure state few chemists have seen (1870), and 
 upon which only two or three had previously experimented ; and 
 yet by one happy discovery and by an investigation which more 
 than almost any other exhibits the value of the synthetic power 
 of modern research this unknown body has been made to yield 
 a colouring matter of the greatest possible value. The truth of 
 this will at once be evident when we learn that the total growth 
 of madder is estimated to reach 47,500 tons per annum, worth 
 45 per ton, and having, therefore, a value of ^2,150,000. Of 
 this nearly one-half is used in the United Kingdom, so that no 
 less a sum than j 1,000,000 is now paid by us for madder grown 
 in foreign countries. This will now, in part at least, go to 
 benefit our own population, as we can now transform our coal 
 into this invaluable colouring matter. 
 
 In an experiment made on a large scale it was found that 
 100 tons of tar yield 0*63 ton of anthracene, or i ton of 
 anthracene can be obtained from the distillation of about 
 2000 tons of coal, not reckoning the quantity of anthracene con- 
 tained in the pitch. 
 
 Madder is the root of several species of Rubia y amongst 
 which the R. tinctorium is the most valued for its dyeing properties. 
 This grows in Holland, Asia Minor, and in the south of France 
 and of Russia. A species native to England is the R. peregrina. 
 This belongs to the order Rubiace<e, the native members of which, 
 as the Galiums, are mostly inconspicuous wild plants. Some of 
 the foreign species are, on the contrary, important plants, such as 
 the cinchona, ipecacuanha, and coffee plants, and these are dis- 
 tinguished for the number and variety of the peculiar principles 
 which they yield, as quinine, cinchonine, caffeine, alizarine. 
 (Thanks to the kindness of Dr Schunck, the speaker was able to 
 show a young madder plant.) 
 
 In spite of the many investigations of madder which have 
 been made, chemists are still in doubt as to the nature of many 
 of its constituents. Some attribute its colouring powers to the 
 presence of at least two substances alizarine and purpurine ; 
 whilst others say that only one of these produces the true 
 madder colours. 
 
 Alizarine was discovered and obtained from madder, as a 
 crystalline sublimate, by Robiquet and Colin in 1831 ; but little 
 importance attached to this discovery until Schunck, in 1848, 
 
THE ARTIFICIAL PRODUCTION OF ALIZARINE 49 
 
 showed that all the finest madder colours contain only alizarine 
 combined with bases and fatty acids. The second colouring 
 matter, termed purpurine, was discovered by Persoz. It con- 
 tributes to the full and fiery red colour in ordinary madder dye- 
 ing, but dyes a bad purple, alizarine being essential to the latter. 
 Purpurine disappears during the purifying processes of soaping, 
 etc., being far less stable than alizarine. It is distinguished from 
 alizarine by its solubility in boiling alum liquor. 
 
 These two colouring principles may likewise be easily dis- 
 tinguished by their spectra, alizarine producing a set of dark 
 absorption-bands, quite different from those of purpurine, which 
 again vary according to the solvent. Alizarine can be obtained 
 in yellow needle-shaped crystals by simple sublimation from the 
 dried madder ; but this colouring matter is, singularly enough, 
 not contained ready formed in the fresh madder root, but is the 
 product of a peculiar decomposition. For a proof that fresh 
 madder does not contain alizarine we have only to extract the 
 moist root with alcohol, when neither the alcoholic extract nor 
 the insoluble residue will be found to possess tinctorial power. 
 We owe this knowledge to the researches of Schunck and 
 Higgin, who have proved that alizarine is produced by a 
 peculiar kind of fermentation which partly occurs in the root on 
 standing, and partly takes place in the dyebeck, when the powdered 
 madder is treated with water. A crystalline glucoside, termed 
 rubianic acid (Schunck), is contained in the root, and it is this 
 which splits up simply into alizarine and glucose. This acid crys- 
 tallises in fine yellow needles, and gives a definite and crystalline 
 potash salt, from which it was shown to contain twenty-six atoms of 
 carbon in the molecule. Hence, as no other product but glucose 
 is formed, it follows that alizarine must contain C 2 e C 12 =C 14 . 
 (This decomposition of rubianic acid into alizarine was shown by 
 boiling with an acid, and adding caustic soda, when the blue 
 solution of alkaline alizarate was seen.) The formation of ali- 
 zarine in extracts of madder root is effected by a ferment peculiar 
 to the plant and called Erythrozym. It is a ferment sui generis, 
 since no other ferment produces the same effect. When mixed 
 with a solution of rubian or rubianic acid, at the ordinary 
 temperature, the latter is rapidly decomposed as with acids. 
 This is what takes place in making fleur de garance. Dyers 
 raise the temperature of their madder-baths gradually up to 
 boiling-point, because the application of a high temperature 
 
 4 
 
50 THE BRITISH COAL-TAR INDUSTRY 
 
 destroys the ferment. When the temperature is gradually raised, 
 the ferment acts upon the glucoside, and produces alizarine. 
 
 That the colouring matter in fresh madder root is not 
 alizarine can be easily shown by rubbing the soft portions of 
 the root on to paper, when a yellow stain will be produced, 
 which, on treatment with an alkali, shows the bright red colour 
 of an alkaline solution of rubian instead of the blue solution 
 of alizarate. 
 
 According to Schunck, the origin of purpurine, and its relation 
 to alizarine, are still involved in obscurity. 
 
 The hypothesis which of late years has done more than any 
 other to stimulate experiment and enlarge our views in organic 
 chemistry is undoubtedly Kekule's theory of the tetrad nature of 
 carbon and his explanation of the constitution of the carbon 
 compounds. In the so-called paraffine group of organic sub- 
 stances, the carbon atoms are supposed to be connected together 
 by single links of the four bonds attached to each atom, thus 
 giving rise to saturated compounds by the attachment of other 
 elements or radicals to the free bonds. In the group of aromatic 
 substances with which we are specially concerned the carbon 
 atoms are more closely linked together, or, in other words, 
 fewer atoms of hydrogen are necessary to saturate an aggrega- 
 tion of carbon atoms than is the case in the other group. We 
 can explain this, upon the assumption of the tetrad character 
 of carbon, by supposing that each carbon atom is attached to 
 its neighbour alternately by one and two bonds. 
 
 Another singular property of these aromatic bodies is that 
 they all contain at least six atoms of carbon, and that the simplest 
 hydrocarbon of which they are made up is benzol, C 6 H 6 . So 
 that we may regard all these aromatic compounds as benzol 
 derivatives, and this hydrocarbon may be considered as the 
 skeleton round which many complicated substances are arranged. 
 So that by the replacement of one atom of hydrogen by (NH 2 ) 
 we obtain aniline, or by (OH) phenol, etc. From the knowledge 
 gained by the investigation on the quinones, Graebe came to 
 the conclusion that alizarine belongs to the quinone series ; and, 
 availing themselves of Baeyer's reaction, by which phenol can 
 be converted into its hydrocarbon benzol, Graebe and Liebermann 
 passed the vapour of natural alizarine obtained from madder 
 over heated zinc-dust, and found that the hydrocarbon they 
 formed was identical in all its properties with anthracene, 
 
THE ARTIFICIAL PRODUCTION OF ALIZARINE 51 
 
 C 14 H 10 , from coal tar. Hence they confirmed Schunck's con- 
 clusions that the molecule of alizarine contained fourteen atoms 
 of carbon. Having thus got hold of the backbone, as it were, 
 of the compound, it only remained for them to clothe the 
 hydrocarbon with the four additional atoms of oxygen, and to 
 take off the two atoms of hydrogen in excess, in order to obtain 
 alizarine. 
 
 Laurent and also Anderson had, many years ago, obtained 
 a body of the composition C 14 H 8 O 2 , and Graebe recognised this 
 as the quinone of anthracene ; and he now only required to re- 
 place in this two atoms of hydrogen by two of hydroxyl (OH), 
 in order to obtain alizarine, which clearly appeared to be a 
 quinone acid 
 
 C 14 H 10 C 14 H 8 (0") 2 C 14 HOH 
 
 (OH 
 
 Anthracene Anthraquinone Alizarine. 
 
 This replacement of hydrogen can be effected by bromine, by 
 which bibromanthraquinone, Ci4H 6 Br 2 O 2 , is formed, and this, 
 on fusion with caustic potash, gives potassium alizarate, yielding 
 pure alizarine on treatment with hydrochloric acid. The high 
 price of bromine rendered this process unavailable for manu- 
 facturing purposes, and hence another plan was simultaneously 
 proposed by several chemists for effecting the same end in a 
 cheaper mode. Use was hereby made of Kekule's and Wurtz's 
 reaction in the formation of sulpho-benzoic acid. On treating 
 anthraquinone with strong sulphuric acid to a high temperature, 
 
 the di-sulpho acid C 14 H 6 O 2 -jgQ 3 TT is formed, and this, on 
 
 heating with concentrated solution of potash, yields the sulphite 
 and alizarate of potassium ; from the latter substance pure 
 alizarine is obtained by the action of acids. 
 
 In the following table we have a statement of the synthetic 
 production of alizarine from its constituent elements : 
 
 SYNTHESIS OF ALIZARINE 
 
 1 . Acetylene by direct union of carbon and hydrogen in electric arc : 
 
 C 2 + H 2 = C 2 H 2 . (Berthelot, 1862.) 
 
 2. Benzol (tri-acetylene) from acetylene by heat : 
 
 C 6 H 6 . (Berthelot, 1866.) 
 
52 THE BRITISH COAL-TAR INDUSTRY 
 
 3. Anthracene from benzol and ethylene : 
 
 (Berthelot, 1866.) 
 
 4. Alizarine from anthracene (Process No. i). 
 
 (Graebe and Liebermann, 1869.) 
 
 (A) Oxyanthracene or anthraquinone by nitric acid : 
 
 C 14 H 6 (OH) 2 . (Anderson, 1861.) 
 
 (B) Bibromanthraquinone by action of bromine : 
 
 C 14 H 8 O 2 + 2Br2 = C 14 H 6 Br 2 O 2 + 2BrH. 
 
 (C) Alizarine by action of caustic potash : 
 C 14 H 6 Br 2 2 + 4 KHO = C 14 H 6 (OK) 2 O 2 + 2 KBr + 2 H 2 O. 
 
 Potassium alizarate. 
 
 5. Alizarine from anthracene (Process No. 2) : 
 
 (Graebe and Caro, Perkin, Schorlemmer and Dale.) 
 
 (A) Disulphoanthraquinonic acid from anthraquinone : 
 C 14 H 6 (OH) 2 + 2 H 2 S0 4 = C U H 6 2 + 2 H 2 O. 
 
 (B) Alizarine from the above by the action of potash : 
 C 14 H 6 2 + 4 KHO - C 14 H 6 2 
 
 Alizarine. 
 
 Mr Perkin states that an intermediate substance is formed in 
 this reaction having the formula C 14 H 6 (O) 2 "s OQO , and this, 
 
 when heated with potash, splits up into alizarine and a sulphite. 
 Other yellow-coloured products are, according to Perkin, con- 
 tained in the alizarine as sent out from his manufactory. The 
 nature of these yellow crystalline bodies is as yet unknown. 
 
 Of the identity of the natural with the artificial alizarine 
 there can be no doubt ; they agree in all their physical and 
 chemical properties. Their absorption-spectra are identical, 
 their tinctorial powers are the same ; the coloured lakes which 
 they form with alumina, iron, and copper salts are of the same 
 tint and possess the same degree of solubility, and these remain 
 alike unaltered by the action of light, so that when they are 
 fixed in the cotton-fibre they yield equally fast colours. 
 
 It is difficult to predict how far the artificial alizarine will 
 in future restrict the growth of madder ; but there is no doubt 
 that for many styles of calico-printing the artificial alizarine is 
 of the greatest value, and we may naturally expect to see very 
 
THE ARTIFICIAL PRODUCTION OF ALIZARINE 53 
 
 important changes effected in this branch of chemical industry 
 in the further practical application of this new discovery. 
 
 CONTRIBUTIONS TO THE HISTORY OF ALIZARINE, C 14 H 8 O 4 
 
 1825. Faraday discovered benzol, C 6 H 6 , in coal-gas oil. 
 
 1831. Robiquet and Colin discovered alizarine in madder root. 
 
 1832. Dumas and Laurent discovered anthracene in coal oils. 
 1848. Schunck gave the composition of alizarine, C 14 H 10 O 4 . 
 1850. Strecker gave the composition of alizarine, C 10 H 6 O 3 . 
 1862. Anderson examined anthracene compounds, C 14 H 10 . 
 
 1865. Kekule explained the constitution of the aromatic compounds. 
 
 1866. Baeyer obtained benzol from phenol. 
 1868. Graebe investigated the quinones. 
 
 1868. Graebe and Liebermann obtained anthracene from alizarine. 
 
 1869. Graebe and Liebermann obtained alizarine from anthracene. 
 
III.: 1879 
 
 THE HISTORY OF ALIZARIN AND ALLIED 
 COLOURING MATTERS 
 
 BY W. H. PERKIN, F.R.S. 
 
 (Journal of the Society of Art *, 1879, p. 572) 
 
 THIS paper gives a very detailed and complete account of the 
 history and synthetic production of alizarin. The main points are 
 summarised in the " Hofmann Memorial Lecture" delivered by Dr 
 Perkin before the Chemical Society in 1896, and reprinted in the 
 present work (see p. 141). 
 
 The ground covered by Perkin' s 1879 r lecture is indicated by the 
 following headings : 
 
 History and Applications of Madder. 
 
 Schunck's Researches on " Natural Alizarin." 
 
 Graebe and Liebermann's Researches. 
 
 Graebe and Liebermanns First Synthesis ^Bromine process). 
 
 The Sulphonic Acid Process (Perkin^ Graebe and Liebermann, 
 
 Caro). 
 
 Impurities in Synthetic Alizarin. 
 Alizarin Orange and Alizarin Blue. 
 The History of the Technical Manufacture of Alizarin in 
 
 Perkins works. 
 The Constitution of Alizarin. 
 
 The concluding paragraphs only of this interesting paper are 
 quoted : 
 
 Having now given an account of the manufacture of artificial 
 alizarin, it will be interesting to inquire into the commercial 
 results of this industry, and, firstly, what has been its influence 
 upon the sale of madder and its derivatives. I mentioned at the 
 
 54 
 
THE HISTORY OF ALIZARIN 
 
 55 
 
 commencement of this paper that the annual value of the im- 
 ports into the United Kingdom, of madder and garancine, from 
 1859 to 1868, amounted to about 1,000,000 sterling, with prices 
 averaging for madder 455. to 505. per cwt., and for garancine, 
 1505. In the subjoined table will be seen the remarkable 
 changes that have taken place in the imports, and also the great 
 reduction in price : 
 
 AVERAGE ANNUAL IMPORTS OF MADDER AND GARANCINE 
 INTO THE UNITED KINGDOM 
 
 Year. 
 
 Madder. 
 
 Garancine. 
 
 French 
 madder. 
 
 Turkey 
 roots. 
 
 Garancine. 
 
 
 cwts. 
 
 cwts. 
 
 
 
 
 1859) 
 1868 j 
 
 35> 8 40 
 
 45>56o 
 
 45s. 
 
 5 os. 
 
 1508. 
 
 1875 
 
 100,280 
 
 25,860 
 
 
 
 
 
 
 
 1876 
 
 59i*37 
 
 I5>396) 
 
 
 
 
 
 or V 
 
 
 
 
 
 
 
 
 
 6,436) 
 
 
 
 
 1877 
 
 38,711 
 
 8,875 
 
 
 
 
 
 
 
 1878 
 
 32,990 
 
 2,79 
 
 1 8s. 
 
 175. 
 
 6 5 s. 
 
 Up to and during 1876 considerable quantities of artificial 
 alizarin were imported from the Continent, and entered at the 
 Customs as garancine or madder, and this having been brought 
 to the notice of the officials, the returns made subsequently are 
 more reliable. The imports of garancine were returned by the 
 Board of Trade in 1876 as 15,396 cwts. when first published, 
 but in the following year, when the figures for 1876 were given 
 for comparison with those of 1877 and 1878, the returns were 
 stated as only 6436 cwts. The erroneous entries were most 
 probably made to evade the penalties for the infringement of 
 patent rights. 1 
 
 Dutch ground madder has been relatively much higher in 
 price than the other qualities. This is owing to its extensive 
 use in wool dyeing. For various reasons artificial alizarin has 
 made but little progress in its application to wool dyeing, and 
 
 1 A method so often resorted to as to render English chemical patents 
 nearly useless as a protection against infringements by foreign manufacturers, 
 the results of this being alike detrimental to the inventor and injurious to the 
 national interests. 
 
56 THE BRITISH COAL-TAR INDUSTRY 
 
 Dutch madder being mostly used for this purpose, its prices 
 have been maintained at from 28s. for ordinary " Ombro " to 
 about 405. to 455. for crop madder. The wool dyers have, 
 however, been working cautiously with artificial alizarin, and 
 now some of them are using it somewhat largely, and considering 
 its cheapness as compared with Dutch madder, no doubt they 
 will soon find how to use it successfully and cease to employ 
 madder. 
 
 The decline in the sale of madder is still rapidly going on. 
 During the first two months of last year the imports were 
 
 Madder 6846 cwts. 
 
 Garancine 533 
 
 During the first two months of this year they were 
 
 Madder 2185 cwts. 
 
 Garancine 175 
 
 or about two-thirds less. And not only so, but the price is still 
 declining. Turkey roots may now be bought at us. per cwt., 
 whereas before artificial alizarin was introduced they were sold, 
 on an average, at 505. At the present prices of madder, its 
 cultivation is unremunerative, and will, undoubtedly, be soon a 
 thing of the past. Such has been the success of artificial alizarin 
 in competing with madder and garancine in this country, and it 
 is equally true of other countries. The quantity of madder 
 grown in all the madder-growing countries of the world prior to 
 1868 is estimated at about 70,000 tons per annum. The amount 
 of artificial alizarin now produced is equal in dyeing power to 
 considerably more than this ; in fact, the lowest estimate I have 
 been able to get for 1878, and which was confirmed from other 
 sources, is 9500 tons, which is equivalent to 950,000 tons of 
 madder. This remarkable result has been arrived at in ten 
 years only. 
 
 To produce this quantity of artificial alizarin, there are about 
 nine manufacturers on the Continent, and one in this country, 
 Messrs Burt, Bolton & Haywood, who have two large works 
 for its production, viz. the original works at Greenford Green, 
 and new ones at Silvertown. 
 
 Graebe and Liebermann, in their paper in the Moniteur 
 Scientifique?- give some statistics of the production of artificial 
 
 1 Moniteur Scientifique, April 1879, 416. 
 
THE HISTORY OF ALIZARIN 
 
 57 
 
 alizarin which, however, require correcting. They also leave 
 out the years 1869 and 1870. In 1869 we had advanced in the 
 manufacture so far as to send colour into the market, the first 
 invoice being dated October 4th, and that year we produced 
 about one ton. In 1870 we produced 40 tons ; in 1871, 220 
 tons ; in 1872, 300 tons ; and in 1873, 435 tons. Up to the 
 end of 1870 we were practically the only makers of this product, 
 one of the largest chemical and coal-tar colour manufacturing 
 firms of Germany, with whom we were in correspondence, stating 
 that in November 1870 they had only lately commenced pro- 
 ducing 50 Ibs. of alizarin, 10 per cent, quality, per day, and that 
 no one else in that country was supplying artificial alizarin ; and 
 in 1871 we were practically the only producers of quantity, at 
 any rate during the first part of the year, for in March 1871 
 the firm already referred to, and who had great opportunities of 
 knowing what was being done in their country, wrote that they 
 had not received knowledge of any establishment but their own 
 manufacturing artificial alizarin. 
 
 In November 1871, however, Messrs Gessert Fr&res 
 announced to the Industrial Society of Mulhouse that they had 
 produced 30,792 kilogrammes of alizarin in paste. This is 
 equal to about 30 tons, an amount which was evidently con- 
 sidered by them a very large quantity. 1 
 
 Graebe and Liebermann's statistics are as follows compared 
 with our production : 
 
 Graebe and Perkin & Sons' 
 
 1869 
 1870 
 1871 
 
 1872 
 1873 
 
 Liebermann. productions. 
 
 Tons. Tons. 
 
 I 
 
 40 
 
 125- 150 220 
 
 4OO- 5OO 300 
 
 900-1000 435 
 
 Without wishing to detract from Graebe and Liebermann's 
 original discovery, we may say, that the birthplace of the manu- 
 facture of artificial alizarin was in England. It was in this 
 country that the difficulties and doubts about the manufacture 
 and supply of the raw material, anthracene, were solved, and 
 the production of artificial alizarin by new processes success- 
 fully accomplished. After these results were obtained in this 
 country, Continental chemists were encouraged to manufacture 
 
 1 Moniteur Scientifique^ April 1879, 416. 
 
5 8 THE BRITISH COAL-TAR INDUSTRY 
 
 on a comparatively large scale, but up to the end of 1873 the 
 English manufacturers had practically no competition in the 
 home market. 
 
 Having considered the amount of artificial alizarin now manu- 
 factured, it will be of interest to see what its money value is. 
 
 Taking the lowest estimate, viz. 9500 tons, and calculating 
 its selling prices at 150 per ton, the annual value amounts to 
 no less than 1,425,000, or nearly a million and a half. 
 
 As a dye, it is now at most not more than one-third of the 
 average price of madder in 18591868. Consequently, in the 
 United Kingdom, when the annual value of madder imported 
 was 1,000,000, the annual saving is very great. 
 
 While collecting the statistics about alizarin, I thought it 
 would be of interest to get, if possible, the statistics of the entire 
 coal-tar colour industry, and to the kindness of H. Caro, of the 
 Badische Anilin und Soda Fabrik, I am indebted for most of 
 the following particulars : 
 
 ESTIMATED VALUE OF THE PRODUCTION OF COAL-TAR 
 COLOURS IN 1878 
 
 Germany . . ^2,000,000, of which four-fifths are exported. 
 
 England . . 450,000 
 
 France . . . 350,000 
 
 Switzerland" . . 350,000 
 
 Total . . .3,150,000 
 
 In referring to the works which have been set up for the 
 purpose of making coal-tar colours, I thought it would be of 
 interest to show a copy of a rough sketch of the first works 
 erected for this purpose as they appeared in 1868, two years 
 after the patent for the mauve was taken out. 
 
 These works were not one year old when sketched, and the 
 practicability of making the mauve commercially had only been 
 proved a short time. In 1873 they had increased to such an 
 extent as to cover about six acres. They are represented at this 
 date by a copy of a photograph. 1 
 
 There are now in this country six coal-tar colour works ; in 
 Germany, no less than seventeen ; in France, about five ; and in 
 
 1 A copy of a photograph of the works as they appeared in 1873, and a 
 facsimile of the sketch referred to in the text, showing the works in 1858, is 
 given in a lithograph issued as a supplement to the Journal of the Society of 
 Arts, May 3oth, 1879. 
 
THE HISTORY OF ALIZARIN 59 
 
 Switzerland, four. There are also three works in Germany and 
 three in France which manufacture aniline in enormous quantities 
 for the production of coal-tar colours. 
 
 Such is the wonderful growth of this industry, which dates 
 only from 1856. It is the fruit of scientific researches in organic 
 chemistry, conducted, mostly, from a scientific point of view ; 
 and, while this industry has made such great progress, it has, in 
 its turn, acted as a handmaid to chemical science, by placing at 
 the disposal of chemists products which otherwise could not have 
 been obtained, and thus an amount of research has been con- 
 ducted through it so extensive that it is difficult to realise, and 
 this may, before long, produce practical fruit to an extent we 
 have no conception of. One very important colouring matter 
 related to coal tar, and one of the original sources of aniline a 
 product of as great importance as alizarin has yet to be pro- 
 duced on the large scale. I refer to indigo. Baeyer has shown 
 that it can be produced artificially, but at present no practical 
 means of accomplishing it have been discovered. No doubt, 
 however, it will not be many years before this is achieved, and 
 the cultivation of the indigo plant shares the fate of madder. 
 
 The Chairman, Prof. F. A. ABEL, C.B., F.R.S., said Mr 
 Perkin had dwelt with very justifiable pride on the fact that 
 England had been the birthplace of this particular branch of 
 industry connected with the coal-tar colours, of which he had 
 given the history in so lucid a manner. He had not, however, 
 recalled to their minds that which was also true, that England 
 was also the birthplace of the entire coal-tar industry, the 
 development of which he had so graphically and clearly narrated. 
 He had also, with the modesty which they all knew him to 
 possess, forgotten to mention that he himself was the inventor 
 and founder of this industry, which must compete in importance 
 and interest with any other industry, either in England or any 
 part of the civilised world. 
 
IV.: i88o 
 
 THE NEWER ARTIFICIAL COLOURING 
 MATTERS DERIVED FROM BENZENE 
 
 BY R. J. FRISWELL, F.C.S., F.I.C. 
 
 (Journal of the Society of Arts^ 1880, p. 444) 
 
 METHYL ANILINE VIOLETS 
 
 IT is, no doubt, well known to many here that the earliest 
 violets obtained by artificial means were those produced by the 
 action of pure aniline, or phenylamine, on roseine (magenta), 
 in the presence of an organic acid. A study of this reaction 
 by Hofmann led to his discovery of the action of the iodides of 
 the alcoholic radicals, methyl and ethyl, on roseine base, with 
 the production of the well-known " Hofmann Violets." These 
 were found to be substitution-products of rosaniline, in which 
 one, two, or three atoms of hydrogen in the molecule are 
 replaced by the radicals methyl or ethyl, according as the 
 iodide of either has been used. 
 
 Now roseine itself is, as is well known, produced by the 
 action of arsenic acid or other oxidising agents on a mixture 
 of aniline and toluidine. The chemical formula then adopted 
 for it led to the conclusion that it was produced by the 
 coalescence of the residues of two molecules of toluidine and 
 one of aniline, thus : 
 
 C 6 H 5 NH 2 + 2 C 6 H 4 CH 3 NH 2 - H 6 = C 20 H 19 N 3 . 
 
 O. and E. Fischer have recently shown that this formula was 
 partly erroneous, and that the reaction could also occur between 
 two molecules of aniline and one of paratoluidine 
 
 2 (C 6 H 5 NH 2 ) + C 6 H 4 CH 3 NH 2 - H 6 - C 19 H W N 8 ; 
 
NEWER ARTIFICIAL COLOURING MATTERS 61 
 
 but this does not affect the inference drawn from what was, till 
 recently, supposed to be the constitutional formula of the body 
 in question, and this inference was that the methylated 
 derivatives of roseine could be obtained by the oxidation of 
 the methylated derivatives of aniline, just as roseine was by the 
 oxidation of aniline and toluidine. The inference was somewhat 
 rash ; the methyl groups in dimethylaniline replace the hydrogens 
 in the amido group, and on oxidation might, perhaps, be 
 destroyed. However, on oxidation, dimethylaniline did, indeed, 
 produce a very brilliant violet colour, which, having been 
 discovered by M. Lauth, and improved and patented by Messrs 
 Poirrier & Chappat, was introduced into commerce under the 
 name of Paris Violet. This achievement led to a demand for 
 the production of the methyl anilines on a large scale, and, in a 
 very short time, this was attained. It was well known that 
 methylaniline could be produced by the action of methyl iodide, 
 or bromide, upon aniline, the dimethyl compound resulting 
 from the use of two molecules of the alcoholic compound ; thus 
 
 C 6 H 5 NH 2 + 2(CH 8 I) = C 6 H 5 N(CH 3 ) 2 + 2 HI ; 
 
 but it was evidently necessary to produce the required compound 
 in a cheaper way. This was eventually done by heating aniline 
 hydrochloride and methylic alcohol together, under pressure, in 
 strong cast-iron vessels, enamelled inside, and known as 
 " autoclaves." Various proportions of the bodies have been 
 employed among others, the following giving good results : 
 Aniline, 33*6 ; hydrochloric acid, 37*9 ; methylic alcohol pure, 
 28-5 ; heat to 250 C. for eight hours. Messrs Poirrier have 
 also employed a mixture of 100 parts aniline and 250 methyl 
 nitrate. In the latter case, the mixture requires only a temperature 
 of 1 00 C. ; but the alcoholic nitrate is an exceedingly dangerous 
 compound to deal with ; in all probability, it was the one that 
 led to the lamented death of Mr E. T. Chapman, and a very 
 disastrous and fatal explosion at Messrs Poirrier's works was 
 also caused by it. 
 
 Methylaniline is now largely made by the action of methyl 
 chloride on aniline. As is well known, the former body has, 
 of late years, been obtained in immense quantities in France, 
 from a product of the destructive distillation of residues obtained 
 in the manufacture of beet sugar. This body reacts upon 
 aniline just as the corresponding iodide or bromide does ; it is 
 
62 THE BRITISH COAL-TAR INDUSTRY 
 
 cheap, the reaction takes place with ease, and a remarkably 
 pure product is produced : in fact, dimethylaniline can now be 
 obtained by the ton, free from unaltered aniline, and containing 
 only 3 per cent, of the monomethylated compound. 
 
 From dimethylaniline the violet is obtained by oxidation ; 
 formerly, various oxidising agents were used, among them a 
 mixture of iodine and potassium chlorate ; it is, however, now 
 well known that very gentle oxidisers will produce the colour 
 if a metallic salt is present, the one preferred being copper. If 
 I heat, in this tube, some copper filings with a mixture of 
 dimethylaniline and chloral hydrate, the whole will shortly 
 become a mass of semi-solid violet. It is, however, obvious 
 that so costly a method could not be employed on a manufacturing 
 scale, and, accordingly, the following process is in very general 
 use : 20 parts pure crystallised cupric nitrate are dissolved 
 in 20 parts of acetic acid ; some common salt is now stirred in 
 to the mixture, which is carefully cooled down to the ordinary 
 temperature, and 50 parts of dimethylaniline are added ; the 
 whole is then thoroughly mixed with about 250 to 300 parts 
 of white sand, and the stiff mass thus produced is moulded into 
 large cakes, 2 feet long by 15 inches wide, and 4 inches thick ; 
 these, arranged on copper plates, are placed in a chamber, and 
 heated to a temperature of 60 C. for forty-eight hours. At the 
 end of that time, they have become perfectly hard and brittle, 
 and of a bright brassy colour. They are broken into a coarse 
 powder and thrown into water, sulphide of sodium being added 
 until the whole of the copper-salt has been decomposed. The 
 mass is now washed with water and extracted with dilute hydro- 
 chloric acid at a boiling temperature. After partial cooling and 
 filtration, to remove some resinous bye-products, the colouring 
 matter is precipitated with common salt, and, after drying, it is 
 ready for use. The sand, which simply serves to spread the 
 mixture over a large surface, can be used for a fresh operation. 
 
 The product thus obtained is very brilliant in colour, and 
 in shade is that known as 3 B, dahlia, etc. ; it is, however, not 
 the bluest that can be produced. The bluest shades are made 
 by dissolving it in alcohol, converting it into base by the cautious 
 addition of caustic soda, and then heating the alcoholic solution 
 of the base with benzyl chloride a body having the formula 
 C 6 H 5 CH 2 C1, and produced by the action of chlorine on 
 toluene. The spirit and unaltered benzyl chloride are re- 
 
NEWER ARTIFICIAL COLOURING MATTERS 63 
 
 covered, and the basic colour, on conversion into the hydro- 
 chloride, is ready for use. In a similar way, by the action of 
 methyl chloride, the well-known methyl green was produced ; 
 it is now, however, replaced by the malachite green, discovered 
 by Oscar Doebner, and produced by the action of one molecule of 
 benzoyl trichloride, C 6 H 5 CC1 3 , on two molecules of dimethyl- 
 aniline or of benzoylhydride, or bitter almond oil, C 6 H 5 COH, on 
 the same, in the presence of zinc chloride or of sulphuric acid. 
 
 The latter colour much surpasses the former in fastness and 
 power of standing rough treatment in the dyeing process. The 
 methyl, and, still more, the iodine green, obtained during the 
 manufacture of blue shades of Hofmann violet were fugitive and 
 easily altered by heat, so that the latter could not be boiled 
 without changing to a violet. 
 
 Before leaving the methylaniline colours, I may briefly allude 
 to a question of scientific interest in connection with them. It is 
 well known that Hofmann himself, at one time, considered the 
 violets obtained by the methylation of rosaniline and those from 
 methylaniline to be identical. On the other hand, there was 
 much evidence against this view, for the methylaniline colour 
 was readily rendered bluer in shade by benzyl chloride, which 
 was almost without action on Hofmann violet ; it was also more 
 brilliant, had a much greater affinity for animal fabrics, and was 
 less permanent when exposed to light. For these reasons, the 
 Hofmann colour is still in demand, and, indeed, has recovered 
 some of the ground it at first lost to the more brilliant colour. 
 The researches of Brunner and Brandenburg, following those of 
 Caro and Graebe, have shown that the methylaniline violets are 
 not identical with those obtained by Hofmann's process. 
 
 DlPHENYLAMINE BLUE AND ALKALI GREEN 
 
 The ordinary aniline blues are obtained by the action of 
 aniline upon roseine base, in the presence of an organic acid, at a 
 temperature which ultimately approaches the boiling-point of 
 the aniline used. The ultimate product of this reaction is an 
 exceedingly intense blue, the hydrochloride of which is known 
 as opal blue, and is, really, the hydrochloride of triphenylrosaniline. 
 This, on dry distillation, yields diphenylamine, and the latter 
 body, on oxidation, yields a blue which is identical with that 
 obtained from rosaniline, but somewhat greener in shade, and is 
 
64 THE BRITISH COAL-TAR INDUSTRY 
 
 therefore in demand for certain uses. The diphenylamine is 
 prepared by heating, under pressure, a mixture of aniline and dry 
 aniline hydrochloride, when the following reaction occurs : 
 
 C 6 H 5 NH 2 + C 6 H 6 NH 2 HC1 = (C 6 H 5 ) 2 NH + NH 4 C1. 
 
 Diphenylamine is readily oxidised if heated with oxalic acid, and 
 the resulting melt, purified from unaltered oxalic acid, diphenyl- 
 amine, and resinous matters, is readily converted into either of 
 the sulphonic compounds discovered by Nicholson. Blues of a 
 redder shade can be also obtained by the oxidation of methyl- or 
 ethyldiphenylamine. 
 
 I have now to call your attention to a green obtained from 
 this body, discovered by Mr R. Meldola, and now under his 
 investigation. It is obtained by the oxidation of a diphenylamine 
 derivative. After oxidation the colour is obtained in a state 
 corresponding to the well-known opal blue, and, like that, forms 
 sulphonic acids. It is remarkable as being the first green obtained 
 having this property. The sodium salt of the sulphonic acid is 
 soluble in water, and, if wool is immersed in this solution (which 
 is nearly colourless), and kept warm, it apparently undergoes but 
 slight change. I have here a piece of Berlin wool which has 
 been thus treated, and subsequently dried. You will observe 
 that it is, apparently, only rather dirtier than undyed wool. 
 When, however, I immerse it in warm water, acidulated with 
 sulphuric acid, a brilliant green is immediately developed. The 
 colour is remarkably fast ; and, since it requires exactly the same 
 dyeing process as do the Nicholson blues for wool, one would 
 have supposed that it would have been much liked by the dyers ; 
 but this is not, at present, the case. It was exhibited at the late 
 Paris Exhibition by the firm of Brooke, Simpson, & Spiller. 
 
 As time is getting on, I must now leave this very interesting 
 field the colours produced by the oxidation of the secondary and 
 tertiary amines after a very brief and incomplete glance at a few 
 of them, and pass on to the consideration of a totally distinct 
 group of colouring matters, which are now attracting much 
 attention in colour-chemists' laboratories, and which have already 
 taken an important place among artificial dyes, though, as yet, 
 the range of shades is somewhat limited. These are obtained 
 from substances produced by the action of nitrites on amido 
 compounds, and are known as the azo yellows, oranges, and 
 scarlets. 
 
THE NEWER ARTIFICIAL COLOURING MATTERS 65 
 
 The effect of nitrites on organic compounds is very various, 
 according to the subsequent treatment they undergo ; thus, if 
 nitrous gas is passed through a solution of diphenylamine in 
 acetic acid, a mixture of nitroso-nitro-diphenylamines results, and 
 this, on heating with an alkali, decomposes so far as the nitroso 
 groups are concerned, and a mixture of mono- and dinitro- 
 diphenylamine results, which was introduced as a yellow dye by 
 Mr R. Meldola. A somewhat similar reaction occurs if the 
 sulphonic acid of alpha-naphthol is similarly treated, and dinitro- 
 naphthol may be obtained ; while, if a nitrite is added to an 
 aniline salt, and the resulting compound boiled, or if rosaniline 
 salts are similarly treated, the whole of the nitrogen is eliminated 
 with effervescence, and phenol in the one case, rosolic acid in the 
 other both of them non-nitrogenous substances result. Before 
 this boiling takes place, there are, however, in the two latter cases, 
 very different bodies in solution ; these bodies, which behave in 
 the manner just mentioned on boiling, are known to chemists as 
 " azo compounds." 
 
 In the earlier days of organic chemistry, the prefix " azo " 
 was applied by Mitscherlich, Laurent, Zinin, and others to 
 many bodies containing nitrogen, such as azo - benzene, 
 C 6 H 5 N=NC 6 H 5 , produced by the imperfect reduction of nitro- 
 benzene, and also to others, like the compounds obtained by 
 Laurent by the action of ammonia on bitter-almond oil and 
 other bodies. In 1864, however, P. Griess published a 
 magnificent memoir, in which he described a number of bodies 
 obtained by the action of nitrous acid on aniline, and various 
 substitution-products obtained therefrom. In this paper, he 
 proposed that the prefix " azo " should be held to mean that 
 the compound to which it was applied contained one atom of 
 nitrogen occupying the place of one atom of hydrogen. This 
 definition is now generally accepted, and thus the term " azo " 
 has obtained a definite signification. 
 
 The azo compounds are, as a rule, very easily prepared ; in 
 most cases, it is only necessary to add a solution of metallic 
 nitrite to an acid solution of a given amide, in order to obtain 
 the diazo compound of the radicle contained in the amide ; 
 thus, if I take a solution of aniline hydrochloride, and add to it 
 an equivalent quantity of sodium nitrite solution, the reaction 
 at once takes place, and the diazobenzene is produced ; it can 
 be readily separated from its solution, and obtained in the solid 
 
 5 
 
66 THE BRITISH COAL-TAR INDUSTRY 
 
 state, one method being to add a solution of potassium dichromate, 
 when the chlorochromate of diazobenzene is produced. This 
 salt, when dry, is terribly explosive, and at one time was 
 suggested for use in warlike operations ; however, it very 
 rapidly decomposes when kept, losing nitrogen, and becoming 
 no longer efficient. 
 
 This explosiveness is readily understood when we consider 
 the constitution of the body which contains the group N=N . 
 It is manifestly in a state of unstable equilibrium, and a very 
 slight disturbance is sufficient to bring about its decomposition ; 
 and, for the same reason, you will at once see that its chemical 
 activity, as measured by its tendency to combine with other 
 bodies, will be great ; so that, if I add to it another molecule 
 of aniline salt, or, what amounts to the same thing, if I add to 
 two molecules of aniline only one of sodium nitrite, the 
 diazobenzene formed at once attacks the free aniline salt, and 
 what is known as diazoamidobenzene is formed, which, in the 
 presence of an aniline salt, becomes amidoazobenzene 
 C 6 H 5 N=NC 6 H 4 NH 2 . The oxalate of this body was once in 
 pretty general use as a yellow dye, but, as it happened to be 
 volatile at a very low temperature, it soon evaporated from the 
 dyed article, and was, therefore, discarded. 
 
 A compound having a very similar constitution and mode 
 of preparation has, however, long been in use, under the name 
 of " Bismarck brown," and is one of the most permanent of the 
 aniline colours. It is obtained as follows : 
 
 Metadinitrobenzene is prepared by boiling ordinary nitro- 
 benzene with nitric acid. The compound thus produced is 
 added cautiously, with constant agitation, to coarse iron borings, 
 kept boiling in a large quantity of water acidulated with hydro- 
 chloric acid. A violent reaction soon commences (I could readily 
 show you the experiment, but for the steam and unpleasant 
 odour produced) ; the four oxygen atoms contained in the 
 dinitrobenzene are replaced by hydrogen, thus : 
 
 4 C 6 H 4 (N0 2 ) 2 -h Fe 15 + 4 OH 2 = 4 C 6 H 4 (NH 2 ) 2 + S (Fe 3 O 4 ). 
 
 We have thus produced diamidobenzene, and this, when 
 purified from a little dissolved iron, is attacked with sodium 
 nitrite solution ; the reaction here is analogous to the one last 
 described, the final product of the reaction being a triamido- 
 azobenzene, the hydrochloride of which constitutes the well- 
 
THE NEWER ARTIFICIAL COLOURING MATTERS 67 
 
 known colouring matter. We have thus two terms of a possible 
 series first, the amido-azobenzene (yellow, volatile, and fugitive), 
 and triamido-azobenzene (brown, and perfectly fast). Dr Witt 
 set himself the task of filling up the intermediate link, expecting 
 an orange colour, and a moderate stability for the diamido- 
 azobenzene he sought. In this he was not disappointed. A 
 study of the two compounds, from a purely scientific point of 
 view, led him to a perfectly accurate prediction ; and the 
 discovery of " chrysoidine," as the new colour was called, and 
 its production by the addition of diazobenzone chloride to a 
 solution of diamidobenzene was one of the first of a series of 
 researches which have, in various hands, enriched our science and 
 our dyers with a number of magnificent colours. 
 
 The further development of these colours commenced with 
 the introduction of a sulphonic group into one of the amido 
 compounds, the conversion of the sulphonic acid thus produced 
 into a diazo body, and then using it as before ; for instance, if 
 sulphanilic acid produced by the action of strong sulphuric acid 
 on aniline is converted into diazosulphanilic acid, and this added 
 to a solution of diamidobenzene-hydrochloride, the scarlet body 
 produced is the sulphonic acid of chrysoidine. Again, the same 
 body will act on resorcine to produce a colour only differing from 
 the last in that it contains hydroxyl instead of amido groups ; 
 this body has been used as a dye, under the name of tropaeoline 
 o. Witt also produced, by substituting diphenylamine for the 
 resorcine, or diamidobenzene, another beautiful orange, known 
 in commerce as tropaeoline oo. Other compounds were sub- 
 sequently prepared, and have obtained greater prominence ; these 
 were those in which a naphthol was substituted for the phenolic 
 or amido portion of the molecule, beautiful oranges being pro- 
 duced by the action of diazobenzene sulphonic acid on both a- 
 and /8-naphthol ; but these colours were much improved by the 
 introduction of sulphonic groups into both portions of the 
 molecule, a- or /3-naphthol-sulphonic acid being, in fact, substituted 
 for the naphthol only ; still, so far, the improvement was in the 
 direction of stability mainly, the shades still being yellow or 
 orange ; the red was yet to come. 
 
 Chemists will not be surprised to hear that the higher homo- 
 logues of benzene are found, when converted into amido com- 
 pounds, to give an increased redness of shade ; thus, with a given 
 phenol or amine, diazosulphotoluidinic acid, which differs from 
 
68 THE BRITISH COAL-TAR INDUSTRY 
 
 diazosulphanilic acid by having an atom of hydrogen in the 
 benzene ring replaced by methyl, gives redder shades than does 
 the latter, while the substitution of another hydrogen in the same 
 way, as is the case with the diazo compound derived from 
 sulphoxylidinic acid, produces a scarlet. Messrs Meister, 
 Lucius & Brtining were among the first to produce a scarlet 
 by this method, but they also introduced both the sulpho 
 groups into one side of the molecule that of the naphthol. In 
 their patent they describe the preparation of two isomeric /3- 
 naphthol-disulphonic acids, the sodium salts of which are 
 differently soluble in alcohol, the most insoluble one giving a 
 redder colour than the other. On one or other of these they act 
 with diazoxylene chloride, produced by the action of a nitrite on 
 xylidine chloride. The most insoluble salt above mentioned gives 
 a scarlet closely approaching cochineal scarlet, and perfectly fast. 
 
 Mr R. Meldola has also taken out a patent for a scarlet, 
 in which no less than three sulpho groups are engaged. He 
 prepares diazosulphoxylidinic acid, and with this acts on /3- 
 naphthol-disulphonic acid ; on the addition of ammonia, the 
 colour is immediately thrown down, as you perceive. This is, 
 after a slight purification, ready for use. By certain modifications, 
 a scarlet, closely approaching the scarlet obtained by dyeing 
 cochineal in the presence of oxychloride of tin, is produced. 
 
 So far, we have only oranges and scarlets by these reactions. 
 Whether other colours can be similarly produced remains to be 
 seen ; but 1 may mention that Mr Meldola has recently com- 
 municated a paper to the Berlin Chemical Society, in which he 
 describes a violet colour unfortunately not a dye obtained 
 in a somewhat similar way. If we act on dimethylaniline the 
 body from which the violets described in the first part of my 
 lecture are derived with a nitrate, not an azo but a nitroso- 
 dimethylaniline is produced, thus : C 6 H 4 NON(CH 3 ) 2 . This 
 body is as ready to combine with others as an azo body is, and 
 does so in a very similar way, the oxygen atom being elimin- 
 ated in the process, so that if we act with it on /3-naphthol the 
 following combination takes place 1 : 
 
 C 6 H 4 .N.N(CH 3 ) 2 
 /3C 10 H 5 OH, 
 
 1 This formula is given under reserve, as a complete investigation of the 
 compound has not yet been published. 
 
THE NEWER ARTIFICIAL COLOURING MATTERS 69 
 
 the oxygen of the nitroso group going off with two hydrogens 
 from the /3-naphthol, the place of which is taken by a group, 
 which is equivalent to azo-dimethylaniline. The colour crys- 
 tallises magnificently, but its dyeing powers are very feeble. 
 
 DISCUSSION 
 
 Mr SPILLER said it would be manifest that the benzene dye 
 industry had of late years made gigantic strides. When he 
 first became connected with the industry it was the rule to 
 select out the benzole of the coal-tar and throw away a large 
 residual product known as dead-oil. But the requirements of 
 the latest forms of colouring matter which had been mentioned, 
 particularly the orange and scarlet, demanded that the dead-oil 
 should be worked up with a view to extract from it the toluene 
 and xylene. Naphthalene had for a great number of years been a 
 perfect bugbear in scientific industry. It was produced in immense 
 quantities in the manufacture of gas, and, whilst by the labours 
 of Perkin and Graebe anthracene had been employed in the 
 manufacture of alizarin, the naphthalene had been thrown away. 
 It was, however, now required for the manufacture of the 
 scarlet described by Mr Friswell. 
 
 Dr H. E. ARMSTRONG said the paper ought to convey a 
 sound lesson to the objectors to abstract science, because practi- 
 cally speaking the whole of these colours were the result of 
 investigations originally undertaken without any practical aim. 
 There was a large amount of material still remaining in coal-tar 
 not utilised, and there was no doubt a great future in that 
 direction. 
 
 It was not more than ten or twelve years ago that it was 
 found that alizarin could be produced artificially, and now 
 practically all the Turkey-red used was produced artificially. 
 A few years ago the diazo compounds were substances which 
 even chemists were almost afraid to handle. They were discovered 
 by Dr P. Griess, and were extremely unstable and difficult to 
 manipulate, and it would have appeared almost laughable that 
 such compounds would be used for producing colouring matters 
 on a large scale. Dr O. Witt's theoretical views with regard 
 to the constitution of colouring matters had been very productive, 
 and frequently enabled chemists to say, not only that a certain 
 body would be a colouring body, but would have a certain shade. 
 
yo THE BRITISH COAL-TAR INDUSTRY 
 
 Mr R. MELDOLA said there was no doubt that a great many 
 of the products that now ran down our drains would one day 
 become quite as valuable as many of those which were at present 
 employed in factories. New diazo compounds of more and more 
 complex constitutions were being discovered continually, and their 
 number might increase indefinitely. 
 
 The Chairman (Prof. CHARLES GRAHAM) said that when it was 
 remembered that Faraday discovered benzene before any of them 
 were born, and that Unverdorben discovered aniline long ago, 
 it was evident that there must have been much pure scientific 
 research carried on before manufacturers were able to make use 
 of it and convert the products of coal-tar distillation into the 
 valuable dyeing materials we now possess. 
 
V.: i88i 
 
 INDIGO AND ITS ARTIFICIAL PRODUCTION 
 
 BY PROFESSOR H. E. ROSCOE, LL.D., F.R.S. 
 (Discourse delivered at the Royal Institution, 2yth May 1881) 
 
 THE first portion of this address deals with the various syntheses 
 of indigotin up to the commercial introduction of ortho-nitro-phenyl 
 propiolic acid in 1881, and with the mode of application of that body. 
 
 Professor Roscoe proceeds as follows : 
 
 The potential importance, from a purely commercial point of 
 view, of the manufacture of synthetic indigo may be judged of 
 by reference to the following statistics, showing that the annual 
 value of the world's growth of indigo is no less than four millions 
 sterling. 
 
 ESTIMATED YEARLY AVERAGE OF THE PRODUCTION OF INDIGO IN THE 
 WORLD, TAKEN FROM THE TOTAL CROP FOR A PERIOD OF TEN YEARS 
 
 
 Pounds 
 weight. 
 
 Pounds 
 sterling. 
 
 Bengal, Tirhoot, Benares, and N.W. India 
 Madras and Kurpah 
 Manilla, Java, Bombay, etc. .... 
 Central America ...... 
 China and elsewhere, consumed in the country 
 
 8,000,000 
 2,200,000 
 
 2,250,000 
 
 2,000,000 
 400,000 
 500,000 
 600,000 
 say 500,000 
 
 4,000,000 
 
 How far the artificial will drive out the natural colouring 
 matter from the market cannot, as has been said, be foreseen. 
 It is interesting, as the only instance of the kind on record, to 
 
72 THE BRITISH COAL-TAR INDUSTRY 
 
 cast a glance at the history of the production of the first of the 
 artificial vegetable colouring matters, alizarin. In this case the 
 increase in the quantity produced since its discovery in 1869 
 has been enormous, such indeed that the artificial colour has 
 now entirely superseded the natural one, to the almost complete 
 annihilation of the growth of madder-root. It appears that 
 whilst for the ten years immediately preceding 1869 the aver- 
 age value of the annual imports of madder-root was over one 
 million sterling, the imports of the same material during last 
 year (1880) amounted only to 24,000; the whole difference 
 being made up by the introduction of artificial alizarin. In 
 1868, no less a quantity than 60,000 tons of madder-root were 
 sent into the market, this containing 600,000 kilos of pure 
 natural alizarin. But ten years later a quantity of artificial 
 alizarin more than equal to the above amount was sent out 
 from the various chemical factories. So that in ten years the 
 artificial production had overtaken the natural growth, and the 
 300,000 or 400,000 acres of land which had hitherto been used 
 for the growth of madder can henceforward be better employed 
 in growing corn or other articles of food. According to returns, 
 for which the speaker had to thank Mr Perkin, the estimated 
 growth of madder in the world previous to 1869 was 90,000 
 tons, of the average value of 45 per ton, representing a total 
 of 4,050,000. 
 
 Last year (1880) the estimated production of the artificial 
 colouring matter was 14,000 tons, but this contains only 10 
 per cent, of pure alizarin. Reckoning i ton of the artificial 
 colouring matter as equal to 9 tons of madder, the whole 
 artificial product is equivalent to 126,000 tons of madder. The 
 present value of these 14,000 tons of alizarin paste, at 122 
 per ton, is 1,568,000. That of 126,000 tons of madder at 
 45 is 5,670,000, or a saving is effected by the use of 
 alizarin of considerably over four millions sterling. In other 
 words, we get our alizarin dyeing done now for less than 
 one-third of the price which we had to pay to have it done 
 with madder. 
 
 Our knowledge concerning the chemistry of alizarin has also 
 proportionately increased since the above date. For whilst at 
 that time only one distinct body having the above composition 
 was known, we are now acquainted with no less than nine out of 
 the ten di-oxyanthraquinones the existence of which is theoreti- 
 
INDIGO AND ITS ARTIFICIAL PRODUCTION 73 
 
 cally possible, according as the positions of the two molecules of 
 hydroxyl are changed. 
 
 -co- 
 
 co- 
 
 Of the nine known di-oxyanthraquinones, only one, viz. 
 alizarin, or that in which the hydroxyls are contained in the 
 position i, 2, is actually used as a colouring agent. Then again, 
 three tri-oxyanthraquinones, C 14 H 5 O 2 (OH) 3 , are known. One 
 of these is contained in madder-root, and has long been known 
 as purpurin. The other tri-oxyanthraquinones can be artificially 
 prepared. One termed anthrapurpurin is an important colour- 
 ing matter, especially valuable to Turkey-red dyers, as giving a 
 full or fiery red. The other, called flavopurpurin, gives an 
 orange dye with alumina mordants. All these various colouring 
 matters can now be artificially produced, and by mixing these in 
 varying proportions a far greater variety of tints can be obtained 
 than was possible with madder alone, and thus the power of 
 diversifying the colour at will is placed in the hands of the dyer 
 and calico-printer. 
 
 It is quite possible that in an analogous way a variety of 
 shades of blue may be ultimately obtained from substituted 
 indigos, and thus our catalogue of coal-tar colours may be still 
 further increased. 
 
 To Englishmen it is a somewhat mortifying reflection, that 
 whilst the raw materials from which all these coal-tar colours 
 are made are produced in our country, the finished and valuable 
 colours are nearly all manufactured in Germany. The crude 
 and inexpensive materials are, therefore, exported by us abroad, 
 to be converted into colours having many hundred times the 
 value, and these expensive colours have again to be bought by 
 English dyers and calico-printers for use in our staple industries. 
 The total annual value of manufactured coal-tar colours amounts 
 to about three and a half millions ; and as England herself, 
 though furnishing all the raw material, makes only a small 
 fraction of this quantity, but uses a large fraction, it is clear 
 that she loses the profit on the manufacture. The causes of 
 
74 THE BRITISH COAL-TAR INDUSTRY 
 
 this fact, which we must acknowledge, viz. that Germany has 
 driven England out of the field in this important branch of 
 chemical manufacture, are probably various. In the first place, 
 there is no doubt that much of the German success is due to 
 the long-continued attention which their numerous universities 
 have paid to the cultivation of organic chemistry as a pure 
 science. For this is carried out with a degree of completeness, 
 and to an extent, to which we in England are as yet strangers. 
 Secondly, much again is to be attributed to the far more general 
 recognition amongst German than amongst English men of 
 business of the value, from a merely mercantile point of view, of 
 high scientific training. In proof of this it may be mentioned, that 
 each of two of the largest German colour-works employs no less a 
 number than from twenty-five to thirty highly educated scientific 
 chemists, at salaries varying from 250 to ^500 or j6oo per 
 annum. A third cause which doubtless exerts a great influence 
 in this matter is the English law of patents. This, in the special 
 case of colouring matters at least, offers no protection to English 
 patentees against foreign infringement, for when these colours 
 are once on the goods they cannot be identified. Foreign 
 infringers can thus lower the price so that only the patentee, 
 if skilful, can compete against them, and no English licensees 
 of the patent can exist. This may to some extent account for 
 the reluctance which English capitalists feel in embarking in 
 the manufacture of artificial colouring matters. That England 
 possesses both in the scientific and in the practical direction 
 ability equal to the occasion, none can doubt. But be that as 
 it may, the whole honour of the discovery of artificial indigo 
 belongs to Germany and to the distinguished chemist Professor 
 Adolf Baeyer, whilst towards the solution of the difficult problem 
 of its economic manufacture the first successful steps have been 
 taken by Dr Caro and the Baden Aniline and Soda Works of 
 Mannheim. 
 
VI. : 1885 
 
 THE COLOURING MATTERS PRODUCED 
 FROM COAL-TAR 
 
 BY W. H. PERKIN, F.R.S. 
 
 (Presidential Address, Society of Chemical Industry, 1885 : 
 Jour. Soc. Chem. Ind., 1885, p. 426) 
 
 TAKING a precedent from some of those who have occupied 
 this chair before me, I have selected for my few remarks to-day 
 the subject in relation to Technical Chemistry, with which I have 
 been personally connected namely, the colouring matters pro- 
 duced from coal-tar products, with some of the lessons its 
 development appears to me to teach us in connection with 
 industrial chemistry. Sir Frederick Abel, in his address in 1883, 
 when speaking of the history of gunpowder, said that " It is one 
 of the most remarkable features connected with the history of 
 gunpowder, that until the last quarter of a century no radical 
 changes should have been introduced into the manufacture and 
 modes of applying this, the first known practically useful 
 explosive agent." It appears to me that this is more or less 
 true of all the older industries, which resulted simply from 
 experiment and observation without any other basis to work 
 from. They have had long histories in which little progress has 
 been made, but of late years, owing to our advanced and rapidly 
 increasing scientific knowledge, they are undergoing great, and 
 in many cases radical, changes. 
 
 The coal-tar colour industry stands in a very different position 
 to our older ones. It has a sharply defined origin, and a very 
 short history dating back only to 1856, and it is not yet twenty-nine 
 years since the date of the first patent. It is an industry which has 
 been founded on scientific discovery, and has developed side by 
 side with it, being in fact a most important handmaid to research, 
 
 75 
 
76 THE BRITISH COAL-TAR INDUSTRY 
 
 which in its turn has repaid it by new discoveries. At the date 
 of its introduction very little was known of the chemistry of 
 colouring matters ; they were always found difficult bodies to 
 investigate, and when produced in reactions were generally 
 regarded as secondary products, and every endeavour was made 
 to get rid of them so that the other products associated with them 
 might be examined ; but now, owing to the very extended study 
 which has been made of these bodies, on account of this industry, 
 and the relationships which have been found to exist between the 
 colour of the compounds and the chemical constitution, it is 
 possible with more or less certainty to predict the colour a com- 
 pound will have before it is produced, and the means which can 
 be used to modify it. 
 
 It will be possible for me to give you only a very brief sketch 
 of the history of this industry in the time at my disposal ; any- 
 thing like a complete account would fill volumes. On account 
 of this I shall not be able to refer except casually to the coal- 
 tar industry itself, the development of which is mainly due 
 to the one under consideration. Nor can I give a consecutive 
 account of the coal-tar colours themselves, because the discovery 
 of new series of colouring matters, and the progress of old ones, 
 necessarily produce overlapping as it were, and renders such a 
 course difficult and confusing. I therefore propose to take them 
 according to the groups we now know them to belong to. I will 
 therefore commence with that which contains the first colouring 
 matter connected with this industry i.e. the mauveine and 
 safranine group of compounds. 
 
 As I already mentioned, the coal-tar colour industry dates 
 from 1856, the discovery of the aniline purple or mauve dye 
 being made during the Easter vacation of that year, and the 
 patent for its production taken out on the 26th of the following 
 August. I have already described elsewhere * how the discovery 
 of this colouring matter was made during the prosecution of 
 scientific research which had for its object the artificial production 
 of quinine, a subject which of late has very much occupied the 
 attention of chemists, though it has not as yet been accomplished. 
 
 When commencing this industry, which was looked upon by 
 many with considerable doubt as to its practicability, the diffi- 
 culties encountered were very numerous on account of its unique 
 character, but few of the processes having their representatives 
 
 1 See p. 5, ante. 
 
COLOURING MATTERS FROM COAL-TAR 77 
 
 in other industries ; the products were also very valuable, so that 
 great care had to be employed with them. Moreover, the success 
 of the product tinctorially had not been proved on the large scale, 
 so that it was necessary to proceed tentatively and not launch out 
 too rapidly. 
 
 Aniline, as is well known, was at this period a rare body, 
 originally obtained from indigo by Unverdorben in 1826 ; for 
 its production from benzene we are first indebted to the discovery 
 of nitrobenzene in 1834 by Mitscherlich, and then to Zinin, who 
 found that this substance when submitted to certain reducing 
 agents produced a base which was eventually identified as aniline. 
 It was not long before the date of this industry that a method 
 of producing this base from nitrobenzene, with greater ease than 
 by the process of Zinin, was discovered ; and it is to Bechamp 
 we are indebted for this, who found that the reduction might be 
 easily accomplished by means of iron filings and acetic acid. Had 
 this discovery not been made, aniline could not have been pro- 
 duced sufficiently cheap to be used for the production of colour- 
 ing matters. And it is interesting to note that this process of 
 Bechamp, slightly modified, is the one used to-day for the pro- 
 duction not only of this base, but its homologues and analogous 
 compounds. 
 
 It was not long before the difficulties of producing nitro- 
 benzene were to a great extent overcome. Messrs Simpson, 
 Maule & Nicholson also began to experiment on the production 
 of nitrobenzene, and after a time were able to produce it at a 
 sufficiently low cost to be able to supply us with part of our 
 requirements. I mention this in passing because it was the 
 starting-point of the history of the connection of this firm with 
 artificial production of colouring matter, which they carried on 
 so successfully afterwards. 
 
 After the mauve was discovered it was necessary to teach 
 dyers how to use it. Being an organic base, it is opposite in 
 properties to the vegetable colouring matter, and therefore the 
 ordinary methods of application were not generally useful, and 
 much time had to be spent in dye-houses and print-works in the 
 early days of this product in reference to this subject, and at that 
 time the question of fastness to light, soap, and bleaching liquor 
 was much insisted on. Fortunately for the future of the coal-tar 
 colour industry, although the mauve would not resist bleaching 
 liquor well, it proved to be a very fast colour the fastest purple 
 
7 8 THE BRITISH COAL-TAR INDUSTRY 
 
 yet produced, I believe and thus its introduction became rapid. 
 After this the love of brilliancy of colour which it had induced 
 caused less attention to be given to the subject of fastness. I 
 quite think that had this, the first coal-tar colouring matter, 
 yielded colours as fugitive as some which have since been used, 
 this industry would probably have been, to say the least, much 
 delayed in its progress ; so that it will be seen the mauve had to 
 bear all the burdens of the difficulties incident on the inauguration 
 of this industry, the future products being free from these 
 impediments. The importance of this colouring matter after its 
 success was established was quickly recognised in France, and its 
 manufacture commenced there. This soon resulted in its importa- 
 tion into this country irrespective of patent rights. As, however, 
 the foreign manufacturer employed responsible agents in this 
 country, the law was without difficulty put into operation success- 
 fully unfortunately, however, only to teach Continental manu- 
 facturers the lesson not to employ responsible agents in this 
 country any longer, but, by means of correspondence or travellers 
 to deal directly with the consumers, and this modus operandi 
 (practically, though perhaps not theoretically) enabled them to 
 ignore the existence of patents, and import their products freely 
 into this country. On this point I shall have to speak again 
 further on. The mauve was first employed in silk dyeing in 
 London, Messrs Thomas Keith & Sons, of Bethnal Green, being 
 the first to use it. The second application was calico printing, 
 Messrs James Black & Co., of Glasgow, being the first to 
 employ it largely for this purpose. It afterwards was extended 
 to other trades. 
 
 With reference to the chemical history of this dye, although 
 it had been submitted to analysis very soon after its discovery, 
 its formula, or rather the formula of its principal constituent 
 " mauveine," was not established until some time after it had 
 become a commercial product, and was prepared in a crystalline 
 condition. It was then shown to have the composition C 27 H 24 N 4 
 (Proc. R.S.y xiii. 170). 
 
 It was found to be a very powerful base, decomposing 
 ammonia salts with evolution of ammonia, and combining with 
 carbonic acid to form a carbonate. Its ordinary salts are pro- 
 duced by its combination with one molecule of a monobasic 
 acid, its hydrochloride having the formula C 2 7H 2 4N 4 HC1. 
 
 In concentrated sulphuric acid mauveine dissolves with a dirty 
 
COLOURING MATTERS FROM COAL-TAR 79 
 
 green colour, changing to blue on slight dilution, and back to 
 purple when thoroughly diluted ; this is a distinctive reaction of 
 this class of colouring matters. Further researches have shown 
 (Jour. Chem. Soc., xxxv. 717732) that in the ordinary commercial 
 product, besides mauveine, there are two other compounds, one 
 possessing a redder shade of colour, the other being remarkable 
 for its great solubility in alcohol. This latter from analysis 
 appears to have the formula C^H^N^ 
 
 The first product, or mauveine, is evidently a derivative of 
 paratoluidine and aniline. The second of orthotoluidine and 
 aniline, and the third of pure aniline. This has been called 
 pseudo-mauveine. It might perhaps be better called pheno- 
 mauveine. 
 
 When boiled with aniline mauveine yields an indigo-blue 
 product, difficultly soluble in alcohol. This change takes place 
 without formation of ammonia, and shows how different 
 mauveine is in its character to rosaniline. 
 
 Runge found that aniline, when treated with dilute chloride 
 of lime, yielded a blue- or violet-coloured solution, which soon 
 underwent change. Some experiments on this, made in 1868 
 (Jour. Chem. Soc., xxii. 25-27), showed that the product which I 
 named " Runge's blue" was a peculiar compound, the salt of 
 an organic base, which itself dissolved in alcohol with a reddish- 
 brown colour, the salts being blue. It is quite different from 
 mauveine, and of no practical value ; but what is interesting is 
 that when exposed to heat, as by boiling a solution of one of 
 its salts, it decomposes with formation of mauveine. 
 
 A beautiful colouring matter was obtained from mauveine 
 by treating it with ethyl iodide. It gives shades of colour of 
 a very red purple tint, and it was therefore called dahlia. It 
 was mostly used in calico delaine and other kinds of printing, 
 but being costly, the production was never very large. This 
 substance is a monoethyl derivative of mauveine, and all 
 attempts to further ethylate this compound have proved fruitless. 
 In properties it appears to be more like an ammonium compound 
 than a displacement product. 
 
 SAFRANINES 
 
 In the preparation of mauveine, a colouring matter was 
 obtained from the liquors, from which it was precipitated, 
 
8o THE BRITISH COAL-TAR INDUSTRY 
 
 yielding beautiful crimson-red shades of colour on silk. The 
 amount produced in this was so small, however, that we were not 
 able to introduce it as a dye. But it was found that it could be 
 produced by the oxidation of the mauve dye itself, and was 
 then manufactured under the name of "aniline pink," but 
 afterwards " safranine." This substance is evidently closely 
 related to mauveine, as it gives the characteristic reaction with 
 sulphuric acid I have already referred to. 
 
 The preparation of this from the mauve dye was too costly 
 to allow of its being brought into general use. However, new 
 processes have been since discovered, by which this and other 
 colouring matters of its class can be produced cheaply. 
 
 The first of these processes consisted in passing nitrous acid 
 into commercial aniline, heating the mixture with arsenic acid, 
 and then extracting the colouring matter produced. Hofmann 
 examined this, and showed that it had the formula C 2 iH 2 oN 4 
 (Ber., vi. 526, 1872). 
 
 By examination of the product which was obtained by 
 oxidising the mauve dye I found it to have the composition 
 C2oH 18 N 4 (Jour. Chem. Soc., xxxv. 731), results which correspond 
 with analyses published by Dale and Schorlemmer (Jour. Chem. Soc., 
 xxxv. 682) obtained from the examination of a similar product. 
 This substance, I also found, was associated with that examined 
 by Hofmann in a product prepared by Messrs Guinon & Co., 
 of Lyons. 
 
 Methods of a more synthetical nature have since then been 
 discovered. O. Witt found that safranine could be obtained from 
 orthoazotoluene and hydrochloride of toluidine at i5O-2oo C. 
 (Bcr., x. 874, 1877). He then found that by oxidising a 
 mixture of one part of paraphenylenediamine, and two parts of 
 aniline, on the application of heat a safranine could be obtained 
 which has the formula C 18 H 16 N 4 , and which is called pheno- 
 safranine. 
 
 The formation of this colouring matter by this and other 
 processes has been studied by Nietzki (Ber., xvi. 464). He 
 finds that the aniline in the reaction, in which paraphenylenedia- 
 mine takes part, may be substituted by other primary monamines, 
 or a mixture of these with dimethylaniline, and thus a large 
 number of these dyes can be obtained. 
 
 Phenosafranine is now produced very largely, and in a pure 
 crystallised condition, and is a very useful dyeing agent. 
 
COLOURING MATTERS FROM COAL-TAR 81 
 
 If we assume that all the safranines are strictly homologous 
 compounds, the formula that Nietzki gives for phenosafranine 
 would make the formula of that examined by Hofmann, and 
 that examined by myself and Dale and Schorlemmer, to be 
 incorrect, and that they should contain two hydrogens more 
 than are assigned to them. This I cannot think is possible from 
 all the analytical results we obtained. 
 
 The constitution of mauveine has not yet been established, 
 and I have still experiments on this subject in hand. This may 
 also be said of safranine, I think, although Nietzki has proposed 
 a formula for it in which nitrogen occupies a similar position 
 to the methane-carbon in the rosaniline series. 
 
 TRIPHENYLMETHANE DERIVATIVES 
 
 We must now go back again to the early days of this 
 industry to consider the next class of compounds viz. 
 triphenylmethane derivatives. 
 
 The industrial success of the mauve dye caused aniline to 
 become a very favourite body to experiment with, and the result 
 was that in 1859 the discovery of that important colouring 
 matter first known as fuchsine or magenta took place. Hofmann 
 had observed in his experiments on the action of carbon tetra- 
 chloride on aniline in 1858 the formation of a red colouring 
 matter, which consisted of this substance as a secondary product 
 of the reaction, but it was M. Verguin who first discovered a 
 process for the transformation of aniline into a red colouring 
 matter of tinctorial value. The discovery of this compound 
 marks a most important fresh departure in the history of coal- 
 tar colours. As I mentioned, the mauve had paved the way 
 for future colouring matters, and this new substance, which could 
 be applied to fabrics by the same methods as the mauve, was 
 most eagerly sought after owing to the brilliancy of its colour, 
 and probably its manufacture was one of the most successful 
 financially of all the aniline colours. 
 
 M. Verguin's process, which consisted in treating commercial 
 aniline with tin tetrachloride, was soon superseded by better 
 processes. The number of patents taken out for the production 
 of this dye was very large, and all imaginable products were 
 claimed as capable of producing it from aniline. The two most 
 important, however, were those in which mercury nitrate and 
 
 6 
 
82 THE BRITISH COAL-TAR INDUSTRY 
 
 arsenic acid were used. The first of these processes, with which 
 I had some experience, required much care to regulate the 
 reaction and prevent deflagration. The next process with 
 arsenic acid, known as Medlock's, was by far the best, and was 
 employed very extensively until the last few years, nitrobenzene 
 being now mostly used as the oxidising agent in the place of 
 arsenic acid. 
 
 The manufacture of magenta, which at this period was often 
 called roseine, was carried on chiefly in this country by Messrs 
 Simpson, Maule & Nicholson, by the arsenic acid process. 
 Mr E. C. Nicholson and Dr A. P. Price, of this firm, worked 
 out the process with great success, and were the first to produce 
 this colouring matter in a pure state. The beautiful display 
 of the crystallised acetate, shown at the Exhibition of 1862, 
 illustrated this fully. 
 
 It was with products supplied by Mr Nicholson that Dr 
 Hofmann made his first researches on this colouring matter. 
 He changed its name from roseine to rosaniline, and found that 
 the base, when in combination with acids, had the formula 
 QoHjgNs. 
 
 The important observation of Nicholson, and the critical 
 experiments of Hofmann, on the necessity of using, not pure 
 aniline, but a mixture of aniline and toluidine for the production 
 of this substance, was made about this period. 1 
 
 The next important step in this industry was the use of 
 rosaniline itself as a source of new colouring matters. For 
 this we are indebted to the experiments of two French chemists, 
 viz. MM. Girard and De Laire, who discovered that rosaniline 
 salts, when heated with aniline, gave violet and blue colouring 
 matters, which they called violet imperial and bleu de Lyon. It 
 is, however, to Mr Nicholson that the credit of producing 
 these bodies, in a practically pure state, belongs. This especially 
 refers to the blue, the product known as opal blue, used by 
 Dr Hofmann in his investigations on the subject, being of great 
 purity. Dr Hofmann showed that these products were phenyl- 
 ated rosanilines, as is now well known, ammonia being given off 
 
 1 In my original patent it was shown that colouring matters could be 
 obtained not only from aniline, but also from toluidine, xylidine, and 
 cumidine these bases, as usually prepared at that date from the hydro- 
 carbons obtained by fractioning coal-tar naphtha, not being pure, but 
 mixtures. 
 
COLOURING MATTERS FROM COAL-TAR 83 
 
 in the reaction. And I may mention in passing that the manu- 
 facture of these blues is now carried on to such a large extent 
 that the ammonia produced in this reaction is collected for the 
 production of its sulphate or other salt. 
 
 One of the difficulties in the way of the new blue was its 
 insolubility in water. Mr Nicholson, however (in 1862), 
 probably thinking of the method used to render indigo soluble, 
 experimented upon the action of sulphuric acid on this com- 
 pound, and he found that it was possible to obtain sulphonic 
 acids from it. One of these, the sodium salt of which is 
 known as Nicholson's or alkali blue, is the monosulphonic acid, 
 which is itself insoluble in water, but forms soluble salts, which 
 can be applied to the goods, and then decomposed by acids. 
 This compound has had much to do with the successful intro- 
 duction of this colouring matter. The other product known as 
 soluble blue is the sodium salt of the trisulphonic acid. 
 
 In the early part of 1864 the Hofmann violets were intro- 
 duced. These, as is well known, are the ethylated rosanilines 
 produced by acting upon rosaniline with ethyliodide. These 
 colouring matters are more brilliant, though much more fugi- 
 tive than mauveine ; but by this time the desire for per- 
 manency was giving way very much to that of brilliancy ; and 
 these colouring matters were quickly taken up by dyers and 
 calico printers. 
 
 About this time some colouring matters derived from phenol 
 were introduced, and which, curiously, are found to belong to 
 the class of substances now under consideration. These were 
 brought forward by Messrs Guinon, Marnas & Bonnet, of 
 Lyons. The first product was aurin, prepared from phenol by 
 means of oxalic and sulphuric acid (Kolbe and Schmitt's process). 
 The next was peonine, obtained by acting upon aurin with 
 ammonia. The third was azuline, prepared by heating aurin 
 with aniline. This last was a blue dye, which has since been 
 shown to consist chiefly of triphenylrosaniline. 
 
 Purple and violet derivatives were also obtained from 
 rosaniline by a process of my own, in which brominated 
 turpentine was employed. These were known as Britannia 
 violets, and were much used. 
 
 Other coloured derivatives were also discovered ; for example, 
 by the action of aldehyde and sulphuric acid, a blue product 
 was obtained, which, when treated with sodium hyposulphite 
 
84 THE BRITISH COAL-TAR INDUSTRY 
 
 or sulphuretted hydrogen water, yielded the well-known aldehyde 
 green. 
 
 On examining the action of acetylchloride on Britannia violet, 
 I obtained a peculiar green, which was used principally by calico 
 printers, and very considerable quantities of acetylchloride were 
 prepared for this purpose. The process was not published. 
 This green was of a blue shade, and was obtained in a crystallised 
 condition in combination with picric acid. The crystals had a 
 golden metallic reflection. 
 
 Soon after this it was noticed that a green compound was 
 produced in the preparation of the Hofmann violets, though 
 generally only in small quantities. It was afterwards found that 
 by making rosaniline react with an excess of methyl iodide 
 it could be produced practically. It was called iodine green ; 
 but the product now manufactured is a chloride. This colour- 
 ing matter gave good candlelight greens. One of its peculiarities 
 is that when heated it is converted into violet methylrosaniline, 
 with loss of methylchloride. 
 
 A new method of producing rosaniline violet was proposed 
 by Lauth, and patented by MM. Porrier & Chappat, in June 
 1866. The process consisted in taking aniline, in which 
 hydrogen had been replaced by an alcohol radical, and oxidising 
 this instead of first preparing rosaniline, and then replacing the 
 hydrogen in the colouring matter by the radical. The product 
 proposed for this purpose was methylaniline. 
 
 Owing to the improved method of methylating aniline, 
 which, I believe, was first proposed by Messrs Girard and 
 De Laire (Bull. Chem. Soc. [2], vii. 360), this process has become 
 a very important one, and large quantities of dimethylaniline 
 are now used, the oxidation being effected by copper salts. The 
 product, according to the researches of Otto Fischer, consists 
 chiefly of pentamethylpararosaniline. 
 
 The most important advance in the production of green 
 colouring matters of the triphenylmethane series was the dis- 
 covery of the benzaldehyde, Victoria, or malachite green. 
 
 In 1877, Otto Fischer, whilst investigating the condensation 
 products of tertiary aromatic bases (Eer.^ x. 1625), obtained by 
 the action of benzaldehyde on dimethylaniline in presence of 
 chloride of zinc, a colourless base of the formula C23H 26 N 2 , the 
 salts of which, when exposed to the air, rapidly oxidised to a 
 fine blue-green dyestuff, which, he thought, would prove to be 
 
COLOURING MATTERS FROM COAL-TAR 85 
 
 of complicated constitution. A little later (Ber. y xi. 950) he 
 showed that by treating this colourless base with some of the 
 ordinary oxidising agents, this green could be more easily 
 produced, and that it stood to the colourless compound in the 
 same relation as rosaniline does to leucaniline. Emil and Otto 
 Fischer afterwards said (Ber., xii. 796) that the first experiments 
 for the production of this green were made by the Badische 
 Anilin- und Soda-Fabrik, in March 1878. About this time 
 Oscar Doebner (Eer.^ xi. 950) found that a green colouring 
 matter was produced by heating benzaldehyde with benzoyltri- 
 chloride and zinc chloride. This product has been found to be 
 identical with that of Fischer's. This green colouring matter 
 is now largely made from benzaldehyde, as this process is found 
 to be the best. A similar compound is also prepared from 
 diethylaniline, and is known as brilliant green. It is a beauti- 
 fully crystalline body. It is rather curious that this produces 
 shades of colour somewhat yellower than the green from 
 dimethylaniline, whereas, being of a higher molecular weight, 
 we should have expected it to be bluer. 
 
 The principal difficulty which had to be contended with in 
 the production of these colouring matters was the need of a 
 supply of benzaldehyde. The usual method of obtaining it 
 from bitter almonds, which was the only one in use, was quite 
 out of the question, so that other sources had to be looked for. 
 The Badische Anilin- und Soda-Fabrik, however, successfully 
 overcame this difficulty. At first they experimented with the 
 process of Lauth and Grimaux, which consists in the oxidation 
 of benzylchloride, with an aqueous solution of lead nitrate ; the 
 product made by this process, however, was too dear. But they 
 found that the decomposition of benzylidenedichloride, by means 
 of water, as observed by Cahours (Ann. Chem. SuppL, ii. 306) and 
 Limpricht (Ann. Chem., 139, 316), gave them a means of produc- 
 ing this compound practically, the reaction being as follows : 
 
 C 6 H 5 CHC1 2 + OH 2 = C 6 H 5 .CHO + 2HC1. 
 
 This process, which they have successfully employed since 
 March 1878, consists in the preparation of benzylidenedichloride 
 from pure toluene, and in the subsequent treatment of this 
 chlorinated body with milk of lime, at 100 C. 
 
 I have stated that the group of colouring matters under 
 consideration are called triphenylmethane derivatives, and to 
 
86 THE BRITISH COAL-TAR INDUSTRY 
 
 show how this has been proved to be the case, I must now refer 
 very briefly to some of the theoretical work which has led to 
 this knowledge. The most important of this refers to rosaniline. 
 I have already drawn attention to the work of Hofmann, which 
 gave us the first knowledge of the composition of this colouring 
 matter, and the further information that it contained hydrogen, 
 which could be displaced by phenyl and alcohol radicals ; but 
 as to the matter of constitution, I think the experiments of 
 Caro and Wanklyn were the first, as they showed the relation 
 which existed between rosaniline and aurin, or rosolic acid, and, 
 in fact, they produced rosolic acid from rosaniline ; but it is to 
 the beautiful researches of Emil and Otto Fischer that we are 
 indebted for a clear knowledge of the constitution of this class 
 of colouring matter. 
 
 But to clear the ground before proceeding further, I must 
 remind you that ordinary commercial rosaniline, or magenta, 
 prepared from aniline and toluidines, is a mixture of colouring 
 matters. This was first known to Mr Nicholson, who found 
 that for the production of the finest blues it was necessary to 
 purify the base and separate one of these before phenylating ; 
 but it is only of later years that the difference between these 
 bodies has been carefully studied and explained. The base 
 examined by Hofmann contained C 2 o, and is the chief constituent 
 of commercial rosaniline. The other contains C 19 , and is now 
 called pararosaniline, because it is produced from aniline and 
 paratoluidine. Similarly, in commercial aurin, two compounds 
 are found, one containing C^, now called rosolic acid, and one 
 containing C 19 , now called aurin ; and these latter can be pro- 
 duced from the corresponding rosanilines ; and Dale and Schor- 
 lemmer have shown that aurin can be also converted into para- 
 rosaniline by the action of ammonia (Jour. Chem. Soc., 
 xxxii. 121). 
 
 Emil and Otto Fischer, however, by submitting the leuco 
 compound of commercial rosaniline to the diazo reaction, 
 obtained the hydrocarbon C 20 H 18 , and from rosaniline prepared 
 from paratoluidine and aniline the hydrocarbon C 19 H 16 . 
 
 And this latter hydrocarbon was found to be identical with 
 Kekule's triphenylmethane 
 
COLOURING MATTERS FROM COAL-TAR 87 
 
 On nitrating this hydrocarbon, they obtained a trinitro 
 derivative, which, when reduced, gave the triamido body, 
 
 NH 2 C 6 H 4 , xC 6 H 4 NH 2 
 [/ ^H 
 
 NH 2 C 6 H, 
 
 which is paraleucaniline, and by carefully heating its hydro- 
 chloride to 1 50- 1 60 C., it was converted into pararosaniline. 
 
 Also they found that by oxidising trinitrotriphenylmethane 
 they obtained trinitrotriphenylcarbinol, and this when reduced 
 gave pararosaniline direct. 
 
 From these results the constitution of the base is evidently 
 
 NH 2 C 6 H 4V yC 6 H 4 NH 2 
 
 NH 2 C 6 H 
 
 Pararosaniline 
 
 the salts the hydrochloride, for example being 
 
 NH 2 C C H 4V /C 6 H 4 NH.HC1 
 >C I 
 
 NH 2 C 6 1 
 
 Pararosaniline hydrochloride. 
 
 Similar results were obtained from the hydrocarbon from 
 rosaniline ; it is tolyldiphenylmethane : 
 
 The rosolic acid and aurin corresponding to the rosanilines 
 are constituted in an analogous manner : 
 
 HOC 6 H 4 \ /C 6 H 4 O HOC 6 H 3 (CH 3 )v /C 6 H 4 O 
 
 >C_ _J and >C I 
 
 HOCH/ HOC, 
 
 > 
 
 H/ 
 
 '6 J 
 Aurin. Rosolic acid. 
 
 From these results we see the beautiful relationships of the 
 various colouring matters of this series to each other, and by it 
 obtain information which is of practical value;, as well as 
 theoretical. The following formulae of a few of these products 
 further illustrate this : 
 
 H \ / H 
 
 Methane (Marsh Gas) >C< 
 
 H/ X H 
 
88 THE BRITISH COAL-TAR INDUSTRY 
 
 Triphenylmethane 
 
 C 1 
 
 H 2 NC 6 H 4 v /C 6 H 4 NH 2 
 
 n 2 ^e n 4\ /^ 
 
 Leucopararosaniline /C\ 
 
 H 2 NC 6 H/ \H 
 
 H 2 NC 6 H 4 v ,C 6 H 4 NH 2 
 Pararosaniline /C\ 
 
 H 2 NC 6 H/ X OH 
 
 .,. H 2 NC 6 H 4V /C 6 H 4 NH.HC1 
 
 Pararosaniline 2 \r/ I 
 
 hydrochloride H 2 NC 6 H 4 < 
 
 L 2 
 
 Triphenylpara- 
 
 rosaniline 
 hydrochloride 
 (Aniline Blue) 
 
 H(C 6 H 5 )NC 6 H 4V /C 6 H 4 N(C 6 H 5 )H 
 H(C 6 H 5 )NC 6 H 4 < 
 
 Hexamethylpara- | (CH 3 ) 2 NC 6 H 4 s v ^ xC 6 H 4 N(CH 3 ) 2 Cl 
 
 rosaniline > /^ ' 
 
 (Methyl Violet) ) (CH 3 ) 2 NC 6 H/ 
 
 (CH 3 ) 2 NC 6 H 4X / C 6 H 4 N(CH 3 ) 2 C1 
 
 Methyl Green >C^- ' 
 
 C1(CH 8 ) 3 NC 6 H/ 
 
 Benzaldehyde (CH 3 ) 2 NC 6 H 4V / C 6 H 4 N(CH 3 ) 2 C1 
 
 or j>C^- ' 
 
 Victoria Green QH/ 
 
 (C 2 H 5 ) 5 NC 6 H 4V / C 6 H 4 N(C 2 H 5 ) 2 C1 
 
 Brilliant Green >C^- ' 
 
 r TT / 
 
 ^6^6 
 
 NaSO 3 ) r w r w / NaSO 3 
 
 H(C 6 H 5 )N f C 6W 3 \ Utl 3 1 N(C6 H 5 ) 
 
 Soluble Blue ^- 
 
 NaS0 3 
 
 The effect of displacing hydrogen by hydrocarbon radicals in 
 rosaniline is seen to result in the shade of colour becoming bluer 
 for each hydrogen displaced the effect of those of high molecular 
 weight, such as phenyl, being to produce the greatest change ; 
 thus triphenylrosaniline is blue, whilst hexamethylrosaniline is 
 blue violet, notwithstanding it contains six hydrogens displaced. 
 
 After all the displacements possible have been effected, as 
 in hexamethylrosaniline, the result of the combination of the 
 
COLOURING MATTERS FROM COAL-TAR 89 
 
 products with halogen compounds of methyl is very interesting. 
 The particular group to which this is attached becomes of the 
 nature of an ammonium group, and the colour does not become 
 bluer, but changes to green i.e. methyl green, and this, like 
 other ammonium compounds, when heated, dissociates with loss 
 of the halogen compound of methyl, and then hexamethylros- 
 aniline is reproduced. Again, if this ammonium group be sub- 
 stituted by phenyl, we also get a green product i.e. Victoria 
 green. 
 
 The structure of some of these bodies has been proved by 
 another most beautiful synthetical process, which has lately 
 come into use a process which enables us now not only to 
 say that we employ the volatile products of the distillation of 
 coal, but also the coke itself ; as carbonic oxide in combination 
 with chlorine (phosgene, or carbon oxychloride) is one of the 
 important agents used. This substance was discovered in 1812 
 by J. Davy. 
 
 In 1876, W. Michler gave an account of his researches on 
 the synthesis of aromatic ketones by means of phosgene 
 (Ber.y ix. 7 1 6), in which he showed by the action of this substance 
 on dimethylaniline that a tetramethylated diamidobenzophenone 
 was obtained. This substance has, therefore, the constitution 
 
 N(CH 3 ) 2 C 6 H 4 - CO - C 6 H 4 (CH 3 ) 2 N. 
 
 The formation of this product takes place in two phases, but I 
 need not enter into that now. 
 
 The first experiments to turn Michler's synthetically prepared 
 tetramethylated diamidobenzophenone to practical account were 
 made by Dr A. Kern, in the works of Bindschedler, at Basle. 
 Dr Kern proved that an agent like phosgene might be produced 
 on a larger scale, and he invented a process to convert Michler's 
 ketone base into methyl purple. This process was derived from 
 the ketone synthesis of triphenylmethane from benzhydrol 
 and benzene, and consisted in preparing the tetramethyldiamido- 
 benzhydrol, and condensing the latter with dimethylaniline ; 
 thus the leuco base of hexamethylrosaniline was obtained, and 
 then oxidised with lead peroxide. This process, which was too 
 costly for practical purposes, has been superseded by one 
 discovered by Dr Caro, who has found that this ketone base 
 can be made to form condensation products with dimethylaniline 
 and other products directly, by the use of phosphorus tri- 
 
90 THE BRITISH COAL-TAR INDUSTRY 
 
 chloride this substance converting it first into a chloride, which 
 then reacts on the dimethylaniline, thus 
 
 N(CH 3 ) 2 C 6 H 4 - CC1 2 - C 6 H 4 (CH 3 ) 2 N + N(CH 3 ) 2 C 6 H 5 
 
 N(CH 3 ) 2 C 6 H 4V /C 6 H 4 (CH 3 ) 2 N,C1 
 
 + HC1 
 
 N(CH 3 ) 2 C 6 H/ 
 
 And this reaction takes place quantitatively, the body being so 
 pure that it readily crystallises from water in prisms, like 
 potassium permanganate, only with a very much more brilliant 
 lustre. These contain water of crystallisation. The condensa- 
 tion can also be effected with phosgene gas. The colouring 
 matter obtained by this means is bluer than that obtained from 
 dimethylaniline by oxidation, which consists chiefly of the 
 pentamethyl compound. 1 
 
 Diethylene can also be made into a ketone with phosgene 
 or carbon oxychloride, and this product condensed with diethyl- 
 aniline yields hexaethylpararosaniline. 
 
 Instead of dimethylaniline, dimethyl-a-naphthylamine can 
 be used, and in this case a beautiful blue colouring matter is 
 obtained, and if a-phenylnaphthylamine be employed, the 
 Victoria blue is produced, and by varying the reaction in this 
 kind of way a great variety of colouring matter can be 
 synthetically prepared. 
 
 With ammonia this ketone condenses to form the new yellow 
 colouring matter, auramine, with aniline phenylauramine. With 
 quinoline it produces a green very similar to Victoria or benzalde- 
 hyde green. I must not, however, spend any more time over 
 this interesting part of the subject, but may say here again we 
 have pure scientific research conducted for its own sake, bearing 
 fruit. The discovery of W. Michler, which remained for seven 
 years a matter of theoretical interest, now comes forward as a 
 matter of practical value. 
 
 ANTHRAQUINONE SERIES 
 
 I must now draw your attention to the important class 
 of colouring matter compounds obtained from anthracene or 
 anthraquinone. 
 
 1 See Caro, Eng. Patents, 4428, September 1883; 4850, i3th March 
 1884; and 5038, i8th March 1884. 
 
COLOURING MATTERS FROM COAL-TAR 91 
 
 Alizarin and the other colouring matters related to it form 
 one of the most important branches of the coal-tar colour 
 industry, and one of special interest, because alizarin was the 
 first instance of the production of a natural colouring matter 
 artificially. It will be quite unnecessary for me here to say 
 much about the madder-root, which was the original source 
 of alizarin, and was grown in such enormous quantities, but 
 now is nearly a thing of the past ; nor will I enter into the early 
 chemical history of alizarin, and all the laborious work which 
 was bestowed upon it by Dr Schunck and others. As you are 
 probably all aware, the relationship of alizarin and its formation from 
 the coal-tar hydrocarbon anthracene was the result of the labours 
 of Graebe and Liebermann, the researches which culminated 
 in this being of a purely scientific nature. The original process 
 for obtaining it has, however, not been found of practical value, 
 but a new one in which sulphuric acid could be used in place 
 of bromine was afterwards discovered by Caro, Graebe and 
 Liebermann in Germany, and by myself in this country, 
 apparently simultaneously. A second process was also dis- 
 covered by me which was worked nearly all the time I was 
 engaged in this industry. In this, dichloranthracene was used 
 instead of anthraquinone, and the product thus obtained yielded 
 colours of a brilliancy which it has been found, even to the 
 present time, difficult to match by the anthraquinone process. 
 
 At the time of the discovery of artificial alizarin, anthracene 
 was not prepared by the tar distillers, as it had no application, 
 and very little was known about it. It was discovered in 1832 
 by Dumas and Laurent. In 185455, when studying under 
 Dr Hofmann, I worked with it for some time, but my results 
 were never published, because, owing to the erroneous formula 
 given to it by Dumas and Laurent, which was accepted, my 
 results would not fit in ; nevertheless the information obtained 
 afterwards proved of great value to me, although at the time 
 the labour spent appeared to be lost labour, showing the value 
 of research even when not successful. The formula of this 
 hydrocarbon was not established until 1862, when it was studied 
 by Dr Anderson. This was only six years before the discovery 
 of Graebe and Liebermann, and, had not the formula of 
 anthracene been established before these chemists commenced 
 their work, the relationship of alizarin to it would not have 
 been discovered, and up to this day it is possible that this 
 
92 THE BRITISH COAL-TAR INDUSTRY 
 
 artificial alizarin industry would not have been in existence. 
 Researches like that of Dr Anderson I have often heard spoken 
 of slightingly, because they don't bear much on their surface ; 
 but who knows what such work may lead to ? Earnest workers 
 cannot be too much encouraged. 
 
 As anthracene was not a commercial product, it was necessary 
 to experiment on its production before alizarin could be 
 manufactured, and not only on the best methods of getting it, 
 but also to get a rough idea of how much could be produced, 
 because unless the hydrocarbon could be obtained in large 
 quantities, artificial alizarin could not compete with madder. 
 In our works at Greenford Green we commenced by distilling 
 pitch ; but afterwards tar distillers were induced to try to 
 separate it from the last runnings of their stills by cooling 
 and then filtering off the crystalline products which separated 
 out, and in fact visits were paid to most of the tar distillers 
 of the United Kingdom, others being corresponded with on 
 the subject, and the result was that in a short time such 
 quantities came in that the distillation of pitch was abandoned. 
 And although much doubt and anxiety prevailed at first as to 
 the possibility of getting a sufficient supply of this raw material, 
 two or three years since there were about 1000 tons of com- 
 mercial anthracene (about 30 per cent.) produced in excess of the 
 requirements, the annual production HI the United Kingdom 
 being estimated at about 6000 tons 30 per cent., or nearly 2000 
 tons pure anthracene. 
 
 Although the colouring matter obtained from anthraquinone 
 or dichloranthracene was at first simply considered as alizarin 
 more or less pure, yet on investigating the matter it was soon 
 found that it contained other colouring matter. To this I drew 
 attention in 1870 (Jour. Chem. Soc. y xxiii. 143, footnote), and in 
 1872 gave the analysis of a product which I named anthra- 
 purpurin, followed by a more extended account a year after- 
 wards (Jour. Chem. Soc., xxv. 659, and xxvi. 425). It was called 
 anthrapurpurin because it is an anthracene derivative having 
 the formula of purpurin, with which it is isomeric. In the latter 
 paper I also referred to another colouring matter dyeing alumina 
 mordants of an orange colour (Jour. Chem. Soc. y xxvi. 425). 
 It was also shown that anthraflavic acid when fused with alkali 
 gave a colouring matter behaving with mordants in the same 
 way (Jour. Chem. Soc. y xxvi. 26] and this has proved to be the 
 
COLOURING MATTERS FROM COAL-TAR 93 
 
 same body. This latter reaction was afterwards more fully 
 studied by Schunck and Roemer, and the colouring matter 
 produced by it was shown also to have the formula of purpurin ; 
 they therefore called it flavopurpurin (Ber., ix. 678), so that the 
 colouring matters formed have proved to be three in number 
 alizarin, anthrapurpurin, and flavopurpurin, all of which are 
 valuable dyes, whereas in madder-root there is only alizarin 
 and purpurin, the latter being of but secondary value. This 
 can now also be produced from anthracene. The researches 
 which have been made on the subject of the conditions under 
 which these different colouring matters are formed, have led 
 to the discovery of methods for their separate production, so 
 that in artificial alizarin, which name commercially embraces 
 all these colouring matters, both mixed and separate, we have 
 more than a simple replacer of madder-root, and as these 
 colouring matters just referred to can be applied with the same 
 mordants, varieties of styles of work can be produced by the 
 calico printer and dyer which before were unknown. Anthra- 
 purpurin is, 1 believe, of as great importance as alizarin itself, 
 and used with it increases its brilliancy, and alone gives very 
 brilliant scarlet shades. 
 
 Artificial alizarin was first produced commercially in this 
 country by my firm at Greenford Green in 1869, when i ton was 
 produced ; in 1870, 40 tons were made ; in 1871, 220 tons, and 
 so on increasingly. It was not produced on the Continent 
 until 1871, when, according to Graebe and Liebermann, 125-150 
 tons were made. These weights do not apply to dry colour, 
 but to paste. 
 
 I cannot go into any lengthened account of the chemistry of 
 this industry here ; its development, however, has kept pace 
 with theoretical investigations, in some cases it may be said to 
 have forestalled it. For example, in the old methods of working, 
 more anthrapurpurin than alizarin was produced ; the conditions 
 required to modify this were found out by experiment. 
 According to all our previous knowledge as to the introduction 
 of hydroxyl into a body by the fusion of its sulphonic acid with 
 alkali, a monosulphonic acid should give a monohydroxyl com- 
 pound, and a disulphonic acid a dihydroxyl compound. There- 
 fore to produce alizarin, which is a dihydroxyl compound, an 
 anthraquinone disulphonic acid was thought to be the proper 
 thing to use. By experience this was gradually found to be 
 
94 THE BRITISH COAL-TAR INDUSTRY 
 
 incorrect, a monosulphonic acid being required to produce 
 alizarin, a disulphonic giving anthra or flavopurpurin, the 
 colouring matter not being due to the primary but to a secondary 
 reaction, as was afterwards shown by research the mono and 
 dioxyanthraquinones (the latter known as anthraflavic and 
 isoanthraflavic acids) being the first products of the reaction, and 
 then undergoing oxidation by the caustic alkali employed, 
 yielding the corresponding colouring matter, a portion of the 
 products, however, being at the same time reduced back to 
 anthraquinone. 
 
 A very important improvement preventing this loss by 
 reduction was discovered by J. J. Koch, who found it might be 
 avoided by the use of a small quantity of potassium chlorate 
 with the alkali used in the fusion. 
 
 The amount of caustic soda used in this industry is very 
 large, and at the Badische Anilin- und Soda-Fabrik and, I 
 believe, elsewhere it is made on the spot ; and I must say the 
 cleanly way in which alkali is made in the above works contrasts 
 very favourably with what I have seen in some of the alkali 
 works in this country. 
 
 Like rosaniline, alizarin has now become a material for pre- 
 paring other colouring matters. Of these there are two in 
 use viz. nitroalizarin, which gives orange-yellow shades with 
 alumina mordants, and alizarin blue, a remarkable compound 
 prepared from nitroalizarin by treating it with sulphuric acid and 
 glycerol. This gives shades of colour like indigo. When first 
 discovered, considerable difficulty was found in its application 
 on account of its insolubility ; it has since been found to form 
 a soluble compound with sodium bisulphite, and by this means 
 its application has become much easier. The constitution of 
 the colouring matter derived from anthracene may be represented 
 as follows : 
 
 yCOv /OH* 1 ' 
 
 Alizarin C 6 H 4 < >C 6 H 2 < 
 
 \:CX ' X)H (2 > 
 
 C( 
 
 / 
 Purpurin C fl H 4 < /^g..^-^**. 
 
 XXX X)H< 4) 
 
 /CCX yOH (1) 
 
 Anthrapurpurin (m) HO C 6 H< >C (5 H 2 < 
 
 / \OH (2) 
 
COLOURING MATTERS FROM COAL-TAR 95 
 
 /COv /OH' 1 ' 
 
 Flavopurpurin >HO C 6 H 3 <T >C 6 H 2 < 
 
 \rn/ \< 
 
 OH< 2 > 
 
 XV_,^K xV^n v ' 
 
 Alizarin Orange C 6 H 4 < >C 6 H4OH' 2 ' 
 ^CO/ N NO 2 < 3 
 
 /COv yOH< 1J 
 
 Alizarin Blue C 6 H 4 <^ 
 
 1(4) 
 
 CH=CH-CH 
 
 Those colouring matters under the name of artificial alizarin 
 are the most important of the coal-tar colours, their money value 
 amounting to more than a third of the entire value of all the 
 colours produced in this industry, and at present the price of 
 artificial alizarin compared tinctorially is not more than one-fourth 
 of that of madder or garancine before their production. There 
 are now three works producing it in this country, but the bulk 
 of that used still comes from Germany. 
 
 PHTHALEINES 
 
 The discovery of this class of bodies dates back to 1871, 
 and was the result of the investigation of Baeyer. He found 
 that phenols unite with a number of polybasic acids and with 
 aldehydes, with separation of water when the mixture is heated 
 alone, or with glycerol and sulphuric acid, the compounds formed 
 not being ethers. Those produced when phthalic anhydride is 
 employed, and which embrace those of practical value, are called 
 phthaleines. The first of these discovered by Baeyer was galle'm 
 (Ber.) iv. 457), produced by heating pyrogallol with phthalic 
 anhydride ; its formula is C 2 oH 14 O5 ; by reduction it loses 
 the elements of water and combines with hydrogen, forming 
 coerulem. These colouring matters, which for a long time 
 remained unnoticed, are now being extensively used. 
 
 Later, in 1871, Baeyer discovered resophthalein, or fluorescein 
 (Ber., iv. 555). This substance, which is remarkable for its 
 yellowish-green fluorescence, dyes silk and wool yellow, but 
 does not combine with mordants, and is not a very useful dyeing 
 agent. But it was discovered by Caro in 1874, the subject being 
 afterwards worked out jointly with Baeyer, that fluorescein when 
 brominated yielded that beautiful dyestuff now called cosine ; 
 
9 6 
 
 THE BRITISH COAL-TAR INDUSTRY 
 
 this was introduced into the market in July 1874. Other sub- 
 stitution products were then studied, and the iodine product was 
 found to give bluer shades of red than the bromine derivative. 
 One of the most beautiful colours of this series is the dichlor- 
 tetraiodofluorescein, in the preparation of which dichlorophthalic 
 anhydride is used. It is called phloxine. The methylic ether of 
 eosine and its nitro derivative also have become commercial 
 articles. These bodies are now manufactured in a practically 
 pure condition. Their structure has been made out by research 
 to be as follows : 
 
 Fluorescein 
 
 Eosine. Tetra- | C 6 H 4 
 bromofluorescein > | 
 (Potassium Salt) ) C 
 
 C fi H 3 OH 
 
 C 6 H 3 OH 
 
 C 6 H.Br 2 (OK) 
 
 I 
 O 
 
 C 6 HBr 2 (OK) 
 
 Tetraiodofluorescein 
 (Potassium Salt) 
 
 C 6 HI 2 (OK) 
 i CAx / \ 
 } \ COQ / C \ 
 
 ^C 6 HI 2 (OK) 
 
 Phloxine. Dichloro- ) C 6 H 2 C1 
 tetraiodofluorescein V | 
 (Potassium Salt). ) 
 
 C 6 HI 2 (OK) 
 O 
 C 6 HI 2 OK 
 
 C 6 H 4 x. X C 6 H 2 (OH) 2 
 Gallein I >C< | 
 Y X O 
 
 C 6 H 2 (OH) 2 
 
 COO' 
 
 The introduction of these colouring matters had a great 
 influence on the manufacture of phthalic acid. This acid, it will 
 be remembered, was proposed a good many years since as a source 
 for the production of benzoic acid, which was largely in demand 
 for the manufacture of aniline blues, phthalic acid when carefully 
 treated with lime yielding calcium benzoate. But as phthalic acid 
 was required to be produced in an extensive way, new experi- 
 
COLOURING MATTERS FROM COAL-TAR 97 
 
 ments had to be made on the subject. The difficulties connected 
 with this were surmounted by the Badische Anilin- und Soda- 
 Fabrik, who are now the chief manufacturers of this body and its 
 anhydride, which is the substance required ; when freshly pre- 
 pared it is one of the most beautiful products one can see. 
 
 Phthalic anhydride and dichlorophthalic acid are now also 
 manufactured for the preparation of the bluish shades of fluor- 
 escein derivatives already referred to. But this is not all ; it was 
 not only necessary to produce these in quantity, but it was neces- 
 sary also to produce resorcinol. This substance was originally pre- 
 pared from certain resins, e.g. galbanum by fusing it with potash, 
 or by distilling brazilin, etc. ; both technically impractical processes. 
 It was afterwards produced by fusing various halogen derivatives 
 of phenol and benzene sulphonic acid with alkali ; these also were 
 not practical processes. It was, however, eventually found that 
 it could be produced by fusing metabenzenedisulphonic acid with 
 potash, the original observation being made by Gallik ; and by 
 this process this product, which was a rare compound, is now 
 manufactured and has become a common one, being produced in 
 very large quantities. 
 
 INDIGO SERIES 
 
 Indigo is too well known a substance for me to make any 
 remarks in reference to its history as a colouring matter, and 
 with reference to the chemical side of the question I suppose 
 few substances have had more work bestowed upon them than 
 this body, so that I must confine my few remarks to its artificial 
 formation. There is one point of interest, however, connected 
 with indigo, and that is that it was the original source of aniline, 
 this base being discovered in the products of its destructive 
 distillation by Unverdorben, in 1826, as already mentioned. 
 
 Notwithstanding the large amount of work which has been 
 bestowed upon this colouring matter, its constitution has only 
 been lately arrived at, and for this, and the methods of its 
 artificial formation, we are indebted to the beautiful and laborious 
 researches of Baeyer. The first process for its artificial produc- 
 tion was patented by Baeyer in March 1880. The process 
 consists in preparing orthonitropropiolic acid and acting upon it 
 in presence of an alkali, with a reducing agent, such as grape 
 sugar, xanthate of sodium, etc. : 
 
 2[C 9 H 5 (N0 2 )0 2 ] + H 4 = 2C0 2 + C 16 H 10 N 2 2 + 2 H 2 O. 
 
 7 
 
98 THE BRITISH COAL-TAR INDUSTRY 
 
 This process renders the application of artificial indigo very 
 easy in calico printing, because the products can be applied to the 
 fabric and the reaction then completed, and thus the indigo is 
 formed and fixed in the fibre ; and this process is in use in some 
 of the print-works of Mulhouse, where there is a continued 
 though small demand for orthonitropropiolic acid. Other 
 processes have been discovered by Baeyer for the formation of 
 indigo ; he has found that it can easily be formed from ortho- 
 nitrobenzaldehyde by condensation with bodies containing the 
 CH 3 CO group, such as acetone. 
 
 Hitherto this artificial formation of indigo has not met with 
 much practical success. This does not arise from difficulties in 
 its manufacture, but in its cost compared with natural indigo, 
 which is a very cheap dyestufF. 
 
 So far as it has been manufactured, however, the possibility 
 of this has been entirely dependent upon scientific research 
 disconnected with its study. To prepare nitropropiolic acid it is 
 necessary to begin with cinnamic acid as a raw material. This 
 acid, until 1877, was only obtained from certain balsams, and 
 was a very costly material. It was then discovered that it could 
 be produced with comparative ease by the action of acetic 
 anhydride and an acetate on benzaldehyde (Jour. Chem. Soc., xxxi. 
 428). Caro afterwards found that this process might be 
 simplified by heating a mixture of benzylidene dichloride with 
 sodium acetate, and it is by this process that it is now prepared. 
 
 The constitution of indigo Baeyer represents as follows : 
 
 C 6 H 4 CO CO C 6 H 4 
 NH C=C NH. 
 
 Several derivatives have been made which are interesting 
 dyes, such as methyl indigo, tetrachlor indigo, etc. 
 
 Azo COMPOUNDS 
 
 The commencement of the history of the azo colours in an 
 industrial sense has little to do with the theoretical side of the 
 question, the early products being the offspring of empirical 
 observations, and in no way connected with the theory of the 
 diazo compounds, a condition of things very different from that 
 now existing. Time will not allow me to enter into the beautiful 
 
COLOURING MATTERS FROM COAL-TAR 99 
 
 work of Griess, much of which will be found in the Philo- 
 sophical Transactions for 1864. 
 
 The first definite compound of this class, shown to possess 
 dyeing powers, was a substance discovered by Prof. Church and 
 myself, known first as nitrosonaphthalene, then as azodinaphthyl- 
 diamine, but now called amidoazonaphthalene. This substance, 
 however, was of no practical value, because its salts, which are 
 violet, cannot exist except in the presence of a certain amount of 
 free acid. This substance has since been found of value in the 
 preparation of the Magdala red. 
 
 The first substance of this class sent into the market was the 
 phenylic analogue of amidoazonaphthalene viz. amidoazo- 
 benzene, which was discovered by Mene. It was introduced by 
 Nicholson, who prepared it by a process which has not been 
 published. It was afterwards patented by Dale and Caro in 1 863. 
 It is a yellow dye, but did not command success, because of its 
 volatility. It has, however, since become useful for the manu- 
 facture of induline. 
 
 The first really successful azo colour was Manchester or 
 Bismarck brown (triamidoazobenzene), which is produced by the 
 action of nitrous acid on metadiamidobenzene. 
 
 The next important step took place in 1876, by the discovery 
 of chrysoidine, by Caro and Witt. Independently, this product is 
 prepared by the action of diazobenzene on metadiamidobenzene. 
 About this time the subject began to be worked out on a 
 scientific basis, and since then the number of diazo dyes produced 
 is marvellous, and it will be useless for me to do more than 
 refer to one or two of the most important. About, this period 
 also the value of the sulpho group began to be realised, and this 
 has greatly added to the value of these dyes. 
 
 The first use of the sulpho group in relation to azo colours 
 was in connection with amidoazonaphthalene, patented by myself 
 in 1863. 
 
 During the early history of the coal-tar colours, innumerable 
 experiments were made with naphthalene derivatives to produce 
 colouring matters, but no results of any value were obtained ; 
 the experiments were mostly made with naphthylamine. The 
 first colouring matter that was obtained from it that was of value 
 was Martius's yellow, a dinitronaphthol. After this came the 
 Magdala red, which was not much used. The principal develop- 
 ment of the coal-tar colours of late years has, however, been in 
 
ioo THE BRITISH COAL-TAR INDUSTRY 
 
 connection with diazo reaction. In these reactions /3-naphthol is 
 much used, and this product, which a few years ago was unknown, 
 is now manufactured by tons by fusing naphthalene sulphonic 
 acid with alkali, and is produced at a few pence per pound. 
 Most of the azo colours produced from benzene derivatives are 
 of a yellow or brown colour, but, by taking products of a higher 
 molecular weight, colours of different shades of red are produced. 
 The one which has commanded the greatest success is the scarlet, 
 first known as Meister's scarlet, produced by the action of 
 diazoxylene chloride on the disulphonic acid of /3-naphthol ; its 
 constitution may be represented thus : 
 
 C 6 H 3 (CH 3 ) 2 - N = N - C 10 H 4 (OH)(HS0 3 ) 2 . 
 
 In the formation of bluer shades, diazocumene chloride is used. 
 The cumidine used is now made from xylidene, by the beautiful 
 reaction of Hofmann's, in which an alcohol radical associated with 
 the nitrogen leaves that element, and enters into the hydrocarbon 
 radical. These scarlets have had a very injurious influence on 
 the cochineal market, and have in many cases displaced cochineal. 
 If a-diazonaphthalene chloride be used instead of the xylene 
 or cumene compounds, the colours known as Bordeaux are 
 produced. Then, again, where derivatives of a-naphthol are 
 used, different results are also obtained, so that great varieties of 
 products can be produced. The preparation of these azo colours 
 is a matter of great simplicity, the colouring matter being 
 precipitated by bringing the products together, and, moreover, 
 they can be produced in almost theoretical yields ; hence they 
 are remarkably cheap dyeing agents. The following are the 
 formulae of some of these azo dyes : 
 
 Bismarck Brown. NH 2 C 6 H 4 . N 2 . C 6 H 3 (NH 2 ) 2 HC1. 
 Chrysoidine. C 6 H 5 . N 2 . C 6 H 3 (NH 2 ) 2 HC1. 
 Fast Yellow. KSO 3 . C 6 H 4 . N 2 . C 6 H 4 NH 2 . 
 Manchester Yellow. NaSO 3 . C 6 H 4 . N 2 . C 6 H 4 NHC 6 H 5 . 
 
 Orange. NaSO 3 . C 6 H 4 . N 2 . C 10 H 6 (OH). 
 
 
 
 Fast Red. NaSO 3 . C 10 H 6 . N 2 . C 10 H 6 (OH). 
 
 Ponceau G. C 6 H 5 . N 2 . C 10 H 4 OH(NaSO 3 ) 2 . 
 
 Ponceau 2 R. (CH 3 ) 2 C 6 H 5 . N 2 . C 10 H 4 OH(NaSO 3 ) 2 . 
 
 Bordeau. C 10 H 7 .-N 2 . C 10 H 4 OH(NaSO 3 ) 2 . 
 
COLOURING MATTERS FROM COAL-TAR 101 
 
 From which it will be seen that the colour changes from yellow 
 to red and claret by the increase of the molecular weight of the 
 radicals introduced, and also by the relative position occupied by 
 the groups, etc. 
 
 QUINOLINE COMPOUNDS 
 
 Products of the quinoline series have of late been claiming 
 attention in relation to colouring matters. It will perhaps be 
 remembered that, in the early days of the coal-tar colour industry, 
 a beautiful blue colour belonging to this series, discovered by 
 Greville Williams (Chem. News, nth Oct. 1860, 219), was intro- 
 duced. This substance was called cyanine. Its employment as 
 a dye for silk at first produced quite a sensation, on account of 
 the beauty of the colour ; but unfortunately it was too fugitive 
 to be of any practical value. Recent researches have shown that 
 chrysaniline is also to be regarded as a body of the quinoline 
 class. Alizarin blue, and the beautiful yellow dye obtained from 
 acetanilide by Fischer, and known as flavaniline, are found also 
 to belong to this class of substances. 
 
 Other colouring matters which have since been prepared 
 from quinoline direct might be referred to did time permit. 
 The peculiar green which is produced by the condensation of 
 tetramethyldiphenylketone with quinoline is of interest, because 
 the introduction of this quinoline has a very different influence 
 on the resulting colouring matter from that of groups containing 
 amidogen in fact, it appears to act more like phenyl, as the 
 green is very analogous to benzaldehyde green. 
 
 There is a very interesting new manufacture growing out of 
 the coal-tar colour industry, and that is the preparation of 
 derivatives of quinoline as substitutes for quinine. I have 
 mentioned that much work has of late been directed to the study 
 of quinine itself, and although the artificial formation of this 
 substance has not yet been discovered, new bodies have been 
 obtained during these investigations which are thought to possess 
 valuable medicinal properties. This is rather a remarkable 
 development from this industry, seeing that it is owing to 
 experiments made on the artificial formation of quinine that it 
 owes its foundation. 
 
 There is another peculiar colouring matter I have not yet 
 referred to peculiar, as it contains sulphur. I refer to 
 methylene blue, a very valuable dye, the constitution of which 
 
102 THE BRITISH COAL-TAR INDUSTRY 
 
 has been so well worked out by Bernthsen. I feel I must be 
 content with this slight reference to it. 
 
 As 1 have shown, the coal-tar colour industry originated in 
 this country, where for some time it was solely carried on. The 
 second impulse was from France in the discovery of magenta and 
 its blue and purple phenyl derivatives, which were soon brought 
 to a state of great purity in this country. The Hofmann violets 
 were then discovered and produced also in this country, several 
 other colours being perfected and largely used. By this time 
 the manufacture of coal-tar colouring matter had made some 
 progress in Germany and Switzerland ; crude products in a cheap 
 form were first made, but improvements soon followed. The 
 subject of these colouring matters was taken up with great 
 earnestness in the German laboratories, so much so that it was 
 stated at one time that this industry was acting injuriously to 
 science, as it had diverted an undue amount of attention from 
 other subjects. Time has, however, proved the groundlessness 
 of this statement. This laboratory work, as well as research 
 work generally, fitted a number of highly trained chemists to 
 enter the colour works, where they soon improved the processes, 
 and thus they were able to produce products of a quality to 
 compete with those of English manufacture, which had, owing 
 to their purity, given superior and more reliable shades of colour 
 in the hands of the dyer ; and the result of the application of 
 such scientific labour to this industry is that Germany produces 
 products of the highest class and at the lowest price. The fact 
 that Germany is now the headquarters of this industry, raises 
 the important question, Why has England allowed this state of 
 things to come about ? All the raw materials are produced in 
 this country, both the products from coal and the other chemicals 
 required, and, as we have seen, the industry originated and was 
 first carried on here, and, in addition, we are the greatest con- 
 sumers of the colouring matters. This fact is well worth 
 considering, and it is many-sided. In my opinion, the patent 
 laws, and the difficulty of preventing infringements from abroad, 
 was one cause which may have prevented this country from 
 maintaining its first position. 
 
 When speaking of the early history of the first coal-tar colour 
 mauveine, I referred to this class of infringement and how it was 
 first met by the proceedings taken against the agents employed 
 in this country, and that this course was so far successful, but 
 
COLOURING MATTERS FROM COAL-TAR 103 
 
 only pointed out how easily the law could be evaded if foreign 
 manufacturers gave up responsible agents and sold direct to the 
 consumers. There being no duties on such articles, no assistance 
 could be obtained at the Customs, and the colouring matters were 
 generally declared under the name of vegetable dyes or extracts, 
 so that it was impossible to stop them entering the country, and 
 even when found, owing to the onus of proof of their being 
 manufactured by the patentee's process resting with the patentee, 
 an almost insurmountable difficulty was raised, as in most cases no 
 traces of the products used in the preparation were left in the 
 colouring matter. The only other proceedings which could be 
 instituted were against the consumer ; here again the difficulties 
 were practically insuperable. 
 
 In most cases the consumers were using the patentee's 
 products to some extent, and it was impossible to know to what 
 extent ; in fact, without going into the many details connected 
 with this point, it may be assumed that in most cases proceeding 
 against a consumer of this kind of article is practically useless. 
 
 The result of this infringement, by importation from abroad, 
 is that a patentee had to compete against all other manufacturers 
 with the exception of his own countrymen. 
 
 There can be but little doubt that this state of things has 
 had much to do with preventing the development of this 
 industry, and crippling enterprise in this country, as it prevented 
 manufacturers even from working under royalties, there being no 
 security whatever except in name. Again, the fact that a 
 foreigner could take a patent in this country, manufacture in his 
 own country, and send the product here, was a great source of 
 loss and mischief to our trade. The new patent laws may 
 probably alter this, but still the difficulty of importation in 
 defiance of patent rights still remains. 
 
 There is another matter which tells much against this country 
 namely, that we are not able to export colour to foreign 
 countries upon the same conditions as foreign manufacturers can 
 into this, because we are met with import duties which handicap 
 us to a prohibitive extent, whereas the foreign manufacturer, 
 being protected in his own country, may maintain his prices 
 there and sell at a lower price in this country ; but what is still 
 more injurious, he may dispose of surplus production in this 
 country at or even below cost price. The injurious effect of such 
 a course upon our market can be easily understood by business 
 
io 4 THE BRITISH COAL-TAR INDUSTRY 
 
 men, and I need not go into it here. These are matters our 
 manufacturers have to contend with, and cannot help themselves ; 
 there is, however, one matter in which they are undoubtedly 
 at fault. 
 
 We find that in Germany the manufacturer understands the 
 value of well-trained chemists, and sympathises with them ; they 
 also realise the value of theoretical chemistry this is a condition 
 of things we don't find in this country. 
 
 Unless I am mistaken, the coal-tar colour industry has acted 
 as the great stimulus to the development of general chemical 
 industries of Germany, and these, by starting with so much 
 scientific aid as they have called to their assistance, have made an 
 amount of progress during the last twenty-five years which is most 
 remarkable. Up to that time England had been the seat of most 
 of the large chemical industries, and the success which we have 
 had appears to me to have produced a feeling of false security, 
 and more attention has been paid by the heads of firms to the 
 markets than to the chemistry of their manufactures. 
 
 1 believe that thirty years ago there were very few chemists 
 employed in chemical works, either in this country or on the 
 Continent. Now there are very few without them ; but in this 
 country they are far less numerous and much less efficient than 
 in Germany, and for this our manufacturers are to a great extent 
 responsible. 1 am told that at some of our large chemical centres, 
 the chemists, or so-called chemists, are sometimes paid not more 
 than could be earned by a bricklayer. If such openings are put 
 by manufacturers before young men, their parents are not likely 
 to give them an expensive scientific training. If they get any, 
 they are not likely to continue it longer than enough to do 
 analysis very imperfectly, say by studying for about nine months. 
 An ordinary tradesman would not be considered efficient unless 
 he passed a much larger apprenticeship than this, but I know 
 teachers complain that it is difficult to get students who are to 
 be works chemists to stay longer than this. The result is that 
 when really efficient men are wanted, they are not to be found, and 
 they have to be got from abroad. In my address to the Chemical 
 Society last year, I referred to the past neglect of research at our 
 chemical schools, so that I need not speak further on that aspect 
 of the subject here, though it is an important one in relation to 
 our industries. 
 
 There is no chasm, as we have already seen, between pure 
 
COLOURING MATTERS FROM COAL-TAR 105 
 
 and applied chemistry, they do not even stand side by side, but 
 are linked together, so that a technical chemist needs to be a 
 thorough chemist, and unless we employ such men we must be 
 at a great disadvantage in relation to foreign manufacturers. 
 
 I have now given a very brief, and therefore a very imperfect, 
 outline of the history of the coal-tar colour industry, an industry 
 to which none other can be compared for its rapid progress. I 
 have drawn your attention to the fact that it is the offspring of 
 scientific research, that in return, as I before stated, it has in 
 many cases given a fresh impulse to research by giving the 
 chemist new products, and also by opening up new subjects of 
 theoretical interest for consideration, and from the fruits thus 
 resulting again reaping further benefit. This linking together 
 of industrial and theoretical chemistry has undoubtedly been the 
 great cause of its wonderful development. We now have not 
 only all the colours of the rainbow, but we have also the more 
 sombre, but often not less useful, colours, and, moreover, there 
 are also great varieties of products of similar colour possessing 
 different properties which fit them for special uses. This industry 
 is also one of no mean dimensions. I have not been able to get 
 any very recent statistical information on this subject, but not- 
 withstanding the great reduction of prices of the products of late 
 years, yet, owing to the extended development it has undergone, 
 the value of the annual output has probably increased and not 
 declined, and from what information I have on the subject I 
 should say it is perhaps not less than ^3,500,000. 
 
 In my remarks I have also been led to refer to some of the 
 points connected with the migration of this industry from this 
 country to Germany, and the probable influence our patent laws 
 had upon this, to the matter of technical education, and the em- 
 ployment of high-class chemists in chemical works. This latter 
 subject is undoubtedly of great importance, and requires the 
 earnest consideration of our manufacturers. If it is found 
 profitable to employ chemists of this class on the Continent, 
 surely it should be found equally profitable to employ them here. 
 In conclusion, I am happy to say there are signs of the coal-tar 
 colour industry returning to our country, in part at any rate, 
 especially in relation to alizarin, for which there are now three 
 large works in existence, and the production of other colouring 
 matters is also increasing. 
 
VII. : i886 
 
 RECENT PROGRESS IN THE 
 COAL-TAR INDUSTRY 
 
 BY PROFESSOR SIR H. E. ROSCOE, M.P., LL.D., F.R.S. 
 (Discourse delivered at the Royal Institution, i6th April 1886) 
 
 THOSE who have read Goethe's episodes from his life, known as 
 Dichtung und Wahrheit^ will remember his description of his 
 visit in 1741 to the burning hill near Dutweiler, a village in 
 the Palatinate. Here he met old Stauf, a coal philosopher, 
 philosophus per ignem^ whose peculiar appearance and more peculiar 
 mode of life, Goethe remarks upon. He was engaged in an un- 
 savoury process of collecting the oils, resin, and tar, obtained in 
 the destructive distillation of coal carried on in a rude form of 
 coke oven. Nor were his labours crowned with pecuniary 
 success, for he complained that he wished to turn the oil and 
 resin into account, and save the soot, on which Goethe adds that 
 in attempting to do too much, the enterprise altogether failed. 
 We can scarcely imagine, however, what Goethe's feelings would 
 have been could he have foreseen the beautiful and useful 
 products which the development of the science of a century and 
 a half has been able to extract from Stauf's evil-smelling oils. 
 With what wonder would he have regarded the synthetic power 
 of modern chemistry, if he could have learnt that not only the 
 brightest, the most varied colours of every tone and shade can be 
 obtained from this coal tar, but that some of the finest perfumes 
 can, by the skill of the chemist, be extracted from it. Nay, that 
 from these apparently useless oils, medicines which vie in potency 
 with the rare vegeto-alkaloids can be obtained, and lastly, perhaps 
 most remarkable of all, that the same raw material may be made 
 to yield an innocuous principle, termed saccharine, possessed of 
 
 106 
 
RECENT PROGRESS IN COAL-TAR INDUSTRY 107 
 
 far greater sweetness than sugar itself. The attainment of such 
 results might well be regarded as savouring of the chimerical 
 dreams of the alchemist, rather than expressions of sober truth, 
 and the modern chemist may ask a riddle more paradoxical than 
 that of Samson, " Out of the burning came forth coolness, and 
 out of the strong came forth sweetness " ; and by no one could 
 the answer be given who had not ploughed with the heifer of 
 science, " What smells stronger than tar and what tastes sweeter 
 than saccharine ? " That these are matters of fact we may assure 
 ourselves by the most convincing of all proofs their money 
 value, and we learn that the annual value of the products now 
 extracted from an unsightly and apparently worthless material, 
 amounts to several millions sterling, whilst the industries based 
 upon these results give employment to thousands of men. 
 
 SOURCES OF THE COAL-TAR PRODUCTS 
 
 In order to obtain these products, whether colours, perfumes, 
 antipyretic medicines, or sweet principle, a certain class of raw 
 material is needed, for it is as impossible to get nutriment from a 
 stone as to procure these products from wrong sources. All 
 organic compounds can be traced back to certain hydrocarbons, 
 which may be said to form the skeletons of the compounds, and 
 these hydrocarbons are divisible into two great classes : (i) the 
 paraffinoid, and (2) the benzenoid hydrocarbons. The chemical 
 differences both in properties and constitution between these two 
 series are well marked. One is the foundation of the fats, whilst 
 the other class gives rise to the essences or aromatic bodies. 
 Now all the colours, finer perfumes, and antipyretic medicines 
 referred to, are members of the latter of these two classes. 
 Hence if we wish to construct these complicated structures, we 
 must employ building materials which are capable of being 
 cemented into a coherent edifice, and therefore we must start 
 with hydrocarbons belonging to the benzenoid series, as any 
 attempt to build up the colours directly from paraffin compounds 
 would prove impracticable. Of all the sources of hydrocarbons, 
 by far the largest is the natural petroleum oils. But these consist 
 almost entirely of paraffins, and hence this source is commercially 
 inapplicable for the production of colours. We have, however, 
 in coal itself, a raw material which by suitable treatment may be 
 made to yield oils of a valuable character. Of these treatments, 
 
io8 THE BRITISH COAL-TAR INDUSTRY 
 
 that followed out in the process of gas-making is the most 
 important, for in addition to illuminating gas in abundant supply, 
 tar is produced which contains principally that benzenoid class of 
 substances already referred to, and which, to use the words of 
 Hofmann, "is one of the most wonderful productions in the 
 whole range of chemistry." The production of these latter as 
 distinguished from the paraffinoid group appears to depend upon 
 a high temperature being employed, to effect the necessary 
 decomposition. 
 
 The quantity of coal made into coke for use in the blast 
 furnace is larger than that distilled for gas-making, no less than 
 between eleven and twelve million tons of coal being annually 
 consumed in the blast furnaces of this country in the form of 
 coke, and being capable of yielding two million tons of volatile 
 products. Up to recent times, however, the whole of these 
 volatile products has been burnt and lost in the coke ovens. 
 But lately, various processes have been devised for preventing 
 this loss, and for obtaining the oils, which might be made avail- 
 able as colour-producing materials. It is, moreover, a somewhat 
 remarkable fact that only in one or two cases have the conditions 
 been complied with which render it possible to obtain the neces- 
 sary benzenoid substances. In the ordinary coking ovens, as 
 well as in the blast furnaces, although the temperature ultimately 
 reached is far in excess of that needed to form the colour-giving 
 hydrocarbons, yet the heating process is carried on so gradually 
 that the volatile products from the coal are obtained in the form 
 of paraffinoid bodies mainly, and hence are useless for colour- 
 making purposes. Amongst the few coking processes in which 
 the heat is suddenly applied, and consequently a yield of colour- 
 giving hydrocarbons is obtained, may be mentioned the patented 
 process of Simon-Carves, the use of which is now spreading in 
 England and abroad. The tar obtained in this process is almost 
 identical in composition with the average gas-works tar, whilst 
 the coke also appears to be equal for iron-smelting purposes to 
 that derived from other coke-ovens. A third source of these 
 oils yet remains to be mentioned, viz. those obtained as a by- 
 product in blast furnaces fed with coal. 
 
 Another condition has, in addition, to be considered in this 
 industry, and that is the nature of the coal employed for distilla- 
 tion. It is a well-known fact that if Lancashire cannel be ex- 
 clusively employed in gas-making a highly luminous gas is 
 
RECENT PROGRESS IN COAL-TAR INDUSTRY 109 
 
 obtained, but the tar is too rich in paraffins to be a source of 
 profit to the tar-distiller, whilst, on the other hand, coal of a 
 more anthracitic character, like that from Newcastle or Stafford- 
 shire, yields a tar too rich in one constituent, viz. naphthalene, 
 and too poor in another, viz. benzene. It is also known to 
 those engaged in carbonising coal principally for the sake of the 
 tar that the coal from different measures, even in the same pit, 
 yields tars of very different constitution. That under these 
 varying conditions products of varying composition are obtained 
 is a result that will surprise no one who considers the compli- 
 cated chemical changes brought about in the process of the 
 destructive distillation of coal. 
 
 HISTORY OF BENZENE AND ITS DERIVATIVES 
 
 Having thus sketched the principles upon which the 
 formation of these valuable tar colours depends, we should do 
 wrong to pass over the history of the discovery of benzene 
 (C 6 H 6 ), which contributed so much to the unlocking of the 
 coal-tar treasury. 
 
 Faraday in 1825 discovered two new hydrocarbons in the 
 oils obtained from portable gas. One of these was found to be 
 butylene (C 4 H 8 ) ; to the other Faraday gave the name of 
 bicarburet of hydrogen, as he ascertained its empirical formula 
 to be C 2 H (C = 6). By exploding its vapour with oxygen, he 
 observed that one volume contains 36 parts by weight of carbon 
 to 3 parts by weight of hydrogen, and its specific gravity com- 
 pared with hydrogen is therefore 39- 1 
 
 Mitscherlich, in 1834, obtained the same hydrocarbon by 
 distillation of benzoic acid, C 7 H 6 O 2 , with slaked lime, and 
 termed it benzin. He assumed that it is formed from benzoic 
 acid simply by removal of carbon dioxide. Liebig denied this, 
 adding the following editorial note to Mitscherlich's memoir : 
 " We have changed the name of the body obtained by Professor 
 Mitscherlich by the dry distillation of benzoic acid and lime, 
 and termed by him benzin, into benzol, because the termination 
 c in ' appears to denote an analogy between strychnine, quinine, 
 etc., bodies to which it does not bear the slightest resemblance, 
 whilst the ending in c ol ' corresponds better to its properties and 
 mode of production. It would have been perhaps better if 
 
 1 Phil. Trans., 1825, p. 440. 
 
no THE BRITISH COAL-TAR INDUSTRY 
 
 the name which the discoverer, Faraday, had given to this body 
 had been retained, as its relation to benzoic acid and benzoyl 
 compounds is not any closer than it is to that of the tar or coal 
 from which it is obtained." 
 
 Almost at the same time Peligot found that the same hydro- 
 carbon occurs, together with benzone, C 13 H 10 O (diphenylketone, 
 CO(C 6 H 5 ) 2 ), in the products of the dry distillation of calcium 
 benzoate. 
 
 The different results obtained by Mitscherlich and Peligot 
 are represented by the following formulae : 
 
 C 7 H 6 O 2 + CaO = C 6 H 6 + CaCO 3 . 
 (C 7 H 5 2 ) 2 Ca =C 13 H 10 O + CaC0 8 . 
 
 Peligot obtained benzene only as a by-product, exactly as in the 
 preparation of acetone (dimethylketone) from calcium acetate ; 
 a certain quantity of marsh gas is always formed. 
 
 It is not clear how Liebig became acquainted with the fact 
 that benzene is formed by the dry distillation of coal, as his 
 pupil Hofmann, who obtained it in 1845 from coal-tar, 
 observes : " It is frequently stated in memoirs and text-books 
 that coal-tar oil contains benzene. I am, however, unacquainted 
 with any research in which this question has been investigated." 
 It is, however, worthy of remark that about the year 1834, at 
 the time when Mitscherlich had converted benzene into nitro- 
 benzene, the distillation of coal-tar was carried out on a large 
 scale in the neighbourhood of Manchester ; the naphtha which 
 was obtained was employed for the purpose of dissolving the 
 residual pitch, and thus obtaining black varnish. Attempts were 
 made to supplant the naphtha obtained from wood-tar, which at 
 that time was much used in the hat factories at Gorton, near 
 Manchester, for the prepartion of " lacquer," by coal-tar naphtha. 
 The substitute, however, did not answer, as the impure naphtha 
 left, on evaporation, so unpleasant a smell that the workmen 
 refused to employ it. It was also known about the year 1838 
 that wood-naphtha contained oxygen, whilst that from coal-tar 
 did not, and hence Mr John Dale attempted to convert the 
 latter into the former, or into some similar substance. By the 
 action of sulphuric acid and potassium nitrate, he obtained a 
 liquid possessing a smell resembling that of bitter almond oil, 
 the properties of which he did not further investigate. This 
 was, however, done in 1842 by Mr John Leigh, who exhibited 
 
RECENT PROGRESS IN COAL-TAR INDUSTRY in 
 
 considerable quantities of benzene, nitrobenzene, and dinitro- 
 benzene, to the Chemical Section of the British Association 
 meeting that year in Manchester. His communication is, how- 
 ever, so printed in the Report that it is not possible from the 
 description to identify the bodies in question. 
 
 Large quantities of benzene were prepared in 1848, under 
 Hofmann's direction, by Mansfield, who proved that the 
 naphtha in coal-tar contains homologues of benzene, which 
 may be separated from it by fractional distillation. On the i yth 
 of February 1856, Mansfield was occupied with the distillation 
 of this hydrocarbon, which he foresaw would find further 
 applications, for the Paris Exhibition, in a still. The liquid 
 in the retort boiled over and took fire, burning Mansfield so 
 severely that he died in a few days. 
 
 The next step in the production of colours from benzene and 
 toluene is the manufacture of nitrobenzene, C 6 H 5 NO 2 , and nitro- 
 toluene, C 7 H 7 NO 2 . The former compound, discovered in 1834 
 by Mitscherlich, was first introduced as a technical product by 
 Collas under the name of artificial oil of bitter almonds, and 
 Mansfield in 1847 patented a process for its manufacture. It is 
 now used for perfuming soap, but mainly for the manufacture of 
 aniline (C 6 H 5 NH 2 ) for aniline blue and aniline black and for 
 magenta. It is made on a very large scale by allowing a 
 mixture of well-cooled fuming nitric acid and strong sulphuric 
 acid to run into benzene contained in cast-iron vessels provided 
 with stirrers. 
 
 To prepare aniline from nitrobenzene, this compound is acted 
 upon with a mixture of iron turnings and hydrochloric acid in a 
 cast-iron vessel. Commercial aniline is a mixture of this com- 
 pound with toluidine obtained from toluene contained in com- 
 mercial benzene. Some idea of the magnitude of this industry 
 may be gained from the fact that in one aniline works near 
 Manchester no less than 500 tons of this material are manu- 
 factured annually. From the year 1857, after Perkin's cele- 
 brated discovery 1 of the aniline colours, up to the present day, 
 the history of the chemistry of the tar products has been that 
 
 1 See Lectures by Professor Hofmann, F.R.S., "On Mauve and Magenta," 
 nth April 1862, and W. H. Perkin, F.R.S., "On the Newest Colouring 
 Matters," i4th May 1869, Proc. Roy. Inst.; also President's Address (Dr 
 Perkin, F.R.S.), Journal of Society of Chemical Industry, July 1885, "On 
 Coal-Tar Colours" (p. 75, ante). 
 
ii2 THE BRITISH COAL-TAR INDUSTRY 
 
 of a continued series of victories, each one more remarkable 
 than the last. 
 
 COAL-TAR COLOURS 
 
 To even enumerate the different chemical compounds which 
 have been prepared during the last thirty years from coal-tar 
 would be a serious task, whilst to explain their constitution and 
 to exhibit the endless variety of their coloured derivatives which 
 are now manufactured would occupy far more time than is placed 
 at my disposal. Of the industrial importance of these discoveries, 
 the speaker reminded his audience of the wonderful potency of 
 chemical research, as shown by the fact that the greasy material 
 which in 1869 was burnt in the furnaces or sold as a cheap 
 waggon grease at the rate of a few shillings a ton, received two 
 years afterwards, when pressed into cakes, a price of no less than 
 one shilling per pound, and this revolution was caused by Graebe 
 and Liebermann's synthesis of alizarin, the colouring matter of 
 madder, 1 which is now manufactured from anthracene at a rate of 
 more than two millions sterling per annum ; and it is stated that 
 an offer was once made, in the earlier stages of its history, by a 
 manufacturer of anthracene to the Paris authorities to take up the 
 asphalt used in the streets for the purpose of distilling it, in order 
 to recover the crude anthracene. 
 
 Again, we have in the azo scarlets derived from naphthalene 
 a second remarkable instance of the replacement of a natural 
 colouring matter, that of the cochineal insect, by artificial tar- 
 products, and the naphthol yellows are gradually driving out the 
 dyes obtained from wood extracts and berries. It is, however, 
 true that some of the natural dyestuffs appear to withstand the 
 action of light better than their artificial substitutes, and our 
 soldiers' red coats are still dyed with cochineal. 
 
 The introduction of these artificial scarlets has, it is interesting 
 to note, greatly diminished the cultivation of cochineal in the 
 Canaries, where, in its place, tobacco and sugar are now being 
 largely grown. 
 
 Let us next turn to inquire as to the quantities of these 
 various products obtainable by the distillation of one ton of coal 
 
 1 "On the Artificial Production of Alizarin, the Colouring Matter of 
 Madder," by Professor H. E. Roscoe, Proc. Roy. Inst., ist April 1870 (see 
 p. 46, ante)-, also Dr Perkin, F.R.S., "On the History of Alizarin," Journal 
 Society of Arts, 3oth May 1879 (see p. 54, ante). 
 
RECENT PROGRESS IN COAL-TAR INDUSTRY 113 
 
 in a gas-retort. The six most important materials found in gas- 
 tar from which colours can be prepared, are : 
 
 1. Benzene. 4. Metaxylene (from solvent naphtha). 
 
 2. Toluene. 5. Naphthalene. 
 
 3. Phenol. 6. Anthracene. 
 
 The average quantity of each of these six raw materials obtainable 
 by the destructive distillation of one ton of Lancashire coal is 
 seen in Table I. Moreover, this table shows the average amount 
 of certain colours which each of these raw materials yields, viz. : 
 
 1. I ., z iu 4- (Xylidine, 0-07 lb.). 
 
 2. } Ma 8 enta ' ' 62 3 lb - 5. Vermilline scarlet, 7-1 1 Ibs. 
 
 3. Aurin, 1*2 lb. 6. Alizarin, 2*25 Ibs. (20 per cent.). 
 
 Further it shows the dyeing power of the above quantities of 
 each of these colours, all obtained from one ton of coal, viz. : 
 
 *" > Magenta, 500 yards of flannel 27 in. wide. 
 3. Aurin, 120 yards of flannel. 
 4* I Vermilline scarlet, 2560 yards of flannel. 
 6. Alizarin, 255 yards Turkey-red cloth. 
 
 Lastly, to point out still more clearly these relationships, the 
 dyeing power of one pound of coal is seen in the lowest hori- 
 zontal column, and a parti-coloured flag, which exhibits the exact 
 amount of colour obtainable from one pound of Lancashire coal, 
 was exhibited. 
 
 Let us moreover remember, in this context, that no less than 
 ten million tons of coal are used for gas-making every year in 
 this country, and then let us form a notion of the vast colouring 
 power which this quantity of coal represents. 
 
 The several colours here chosen as examples are only a few 
 amongst a very numerous list of varied colour derivatives of each 
 group. Thus we are at present acquainted with about sixteen 
 distinct yellow colours ; about twelve orange ; more than thirty 
 red colours ; about fifteen blues, seven greens, and nine violets ; 
 also a number of browns and blacks, not to speak of mixtures 
 of these several chemical compounds, giving rise to an almost 
 infinite number of shades and tones of colour. These colours 
 are capable of a rough arrangement according as they are origin- 
 ally derived from one or other of the hydrocarbons contained in 
 the coal-tar. The fifty specimens of different colours exhibited 
 
 8 
 
114 THE BRITISH COAL-TAR INDUSTRY 
 
 
 
 
 
 
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RECENT PROGRESS IN COAL-TAR INDUSTRY 115 
 
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 Azo COLOURS 
 
 Amongst the most important of the artificial colouring matters 
 may be classed the so-called azo colours. These colours are 
 chiefly bright scarlets, oranges, reds, and yellows, with a few 
 blues and violets. They owe their existence to the discovery by 
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 can replace hydrogen in phenols and amido compounds. But it 
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 first start in a practical direction to this class of azo colours by 
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 suggestions contained in a paper read before the Chemical Society. 
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 results, but it does not appear that he made practical use of them 
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 having first brought into the market some of the beautiful azo 
 derivatives of naphthol. Griess, therefore, as the original dis- 
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 colours are obtained, may be considered as the grandfather, 
 whilst Roussin and Witt are really the fathers, of the azo-colour 
 industry. Nor must it be forgotten that it is to Perkin we owe 
 the recognition of the value of the sulpho group in relation to 
 azo colours, a discovery patented in 1863. Moreover it is inter- 
 esting to note that changes in colour from yellow to red and 
 claret are effected by the increase in the molecular weights of the 
 radicals introduced as well as by the relative positions occupied 
 by these groups. 
 
 INDOPHENOL 
 
 Witt is also the discoverer of a new blue dyestufF termed 
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 Certain difficulties, however, have arisen in the adoption of this 
 colour on the large scale. The most important use indophenol 
 is at present put to is for producing dark blues on reds dyed 
 with azo colours, both on wool and cotton. The piece goods are 
 
n6 THE BRITISH COAL-TAR INDUSTRY 
 
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RECENT PROGRESS IN COAL-TAR INDUSTRY 117 
 
 dyed a uniform red first, and then printed with indophenol white ; 
 for like indigo itself indophenol yields a colourless body on 
 reduction, and this being a very powerful reducing agent destroys 
 the azo colour, being itself transformed into indophenol blue. 
 The process works with surprising nicety and is very cheap. 
 The blue is formed and the red discharged with such precision 
 that patterns can be produced in which the blue discharge covers 
 a great deal more space than the original red. This new printing 
 process was devised by Mr H. Koechlin, of Lorrach. The reds 
 used for the purpose are in the case of wool the usual azo 
 scarlets, for cotton Congo red. 
 
 ARTIFICIAL INDIGO 
 
 About five years ago the speaker had the honour of bringing 
 before this audience l the remarkable discovery made by Baeyer 
 of the artificial production from coal-tar products of indigo blue. 
 Since that time but little progress has been made in this manu- 
 facture, as the cost of the process, unlike the case of alizarin, has 
 as yet proved too serious to enable the artificial to compete success- 
 fully in the market with the natural indigo. 
 
 Through the kindness of a number of eminent colour manu- 
 facturers in this country and on the Continent, the speaker was 
 enabled to illustrate his subject by a most complete series of 
 specimens both of the colours themselves and of their application 
 to the dyeing and printing of fabrics of all kinds. His thanks 
 are especially due to his friend Mr Ivan Levinstein, of Manchester, 
 for the interesting series of samples of cloth dyed with known 
 quantities of fifty different coal-tar colours, each having a 
 different chemical composition ; also to the same gentleman, 
 and to Messrs Burt, Boulton, & Hay wood, of London, for the 
 interesting and unique series of specimens indicating the absolute 
 quantities of products obtainable from one ton of coal, as well as 
 for much assistance on the part of Mr Levinstein in the prepara- 
 tion of the experimental illustrations for this discourse. To Dr 
 Martius of Berlin for a valuable series of colours, especially the 
 well-known Congo red, made by his firm, including samples of 
 wool dyed therewith, he is also much indebted. For the interest- 
 
 1 "On Indigo and its Artificial Production," Proc. Roy. Inst., 2;th May 
 1 88 1 (see p. 71, ante). 
 
n8 THE BRITISH COAL-TAR INDUSTRY 
 
 ing details concerning indophenol and its applications the speaker 
 owes his thanks to Dr Witt and M. Koechlin. 
 
 COAL-TAR ANTIPYRETIC MEDICINES 
 
 Next in importance to the colour industry comes the still 
 more novel discovery of the synthetical production of antipyretic 
 medicines. 
 
 Up to this time quinine has held undisputed sway as a 
 febrifuge and antiperiodic, but the artificial production of this 
 substance has as yet eluded the grasp of the chemist. Three 
 coal-tar products have, however, been recently prepared which 
 have been found to possess strong febrifuge qualities, which if 
 still in some respects inferior to the natural alkaloids, yet possess 
 most valuable qualities, and are now manufactured in Germany 
 at H6chst and at Ludwigshafen in large quantity. And here it 
 is well to call to mind that the first tar colouring-matter discovered 
 by Perkin (mauve) was obtained in 1856 during the prosecution 
 of a research which had for its object the artificial production of 
 quinine. 
 
 In considering the historical development of this portion of 
 his subject, the speaker added that it is interesting to remember 
 that the initiative in the production of artificial febrifuges was 
 given by Prof. Dewar's discovery in 1881 that quinoline, the 
 basis of these antipyretic medicines, is an aromatic compound, as 
 from it he obtained aniline. Moreover, Dewar and McKendrick 
 were the first to observe that certain pyridine salts act as febri- 
 fuges. So that these gentlemen may be said to be the fathers 
 of the antipyretic medicines, as Witt and Roussin are of the 
 azo-colour industry. 
 
 Katrine, the first of these, was discovered by Prof. O. 
 Fischer, of Munich, in the year 1881, whilst engaged on his 
 investigations of the oxyquinolines. The febrifuge properties of 
 this substance were first noticed by Prof. Filehne of Erlangen. 
 Kairine is manufactured from quinoline, a basic product derived 
 from aniline by heating it with glycerin and nitrobenzene by the 
 following process. When treated with sulphuric acid, it forms 
 quinoline sulphonic acid, and this when fused with caustic soda 
 yields oxyquinoline, which is then reduced by tin and hydro- 
 chloric acid into tetrahydroxyquinoline, and this again on treat- 
 ment with ethyl bromide yields ethyl tetraoxyquinoline or kairine. 
 
RECENT PROGRESS IN COAL-TAR INDUSTRY 119 
 
 The lowering of the temperature of the body by this compound 
 is most remarkable, though, unfortunately, the action is of much 
 shorter duration than that effected by quinine itself ; but on the 
 other hand, with the exception of its burning taste, it exerts no 
 evil effects such as are often observed after administration of large 
 doses of quinine. The commercial article is the hydrochloride, 
 the price is 855. per lb., and the quantity manufactured has lately 
 diminished owing to the discovery of the second artificial febrifuge, 
 antipyrine. 
 
 The following graphical formula shows the constitution of 
 kairine : 
 
 A 
 HC1 
 
 Antipyrine^ the second of these febrifuges, was discovered in 
 1883 by Dr L. Knorr in Erlangen, and its physiological properties 
 were investigated by Prof. Filehne of Erlangen. The materials 
 used in the manufacture of antipyrine are aniline and aceto-acetic 
 ether. The aniline is first converted into phenylhydrazine, a 
 body discovered by Emil Fischer in 1876. This body combines 
 directly with aceto-acetic ether, with separation of water and 
 alcohol, to form a body called pyrazol (C 10 H 10 N 2 O). The 
 methyl derivative of pyrazol derived by treating it with iodide of 
 methyl, is antipyrine, its composition being C U H 12 N 2 O. As a 
 febrifuge, antipyrine is superior in many respects to kairine and 
 even to quinine itself. It equals kairine in the certainty of its 
 action, whilst in its duration it resembles quinine. It is almost 
 tasteless and odourless, is easily soluble in cold water, and takes 
 the form of a white crystalline powder. Its use as a medicine is 
 accompanied by no drawbacks. It occurs in commerce in the 
 free state. The production of antipyrine, in spite of these 
 valuable qualities, is as yet small, its chief employment being in 
 Germany, where it has been successfully used in cases of typhoid 
 epidemic. The price is 6s. per lb. 
 
 Thalline, the third of the artificial febrifuges, is offered as 
 the tartrate and sulphate. It is manufactured by the Badische 
 Company. Thalline is said to be used as an antidote for yellow 
 fever. Its scientific name is tetrahydroparaquinanisol, and it was 
 first prepared by Skraup by the action of methyl iodide and potash 
 on paroxyquinoline. 
 
120 THE BRITISH COAL-TAR INDUSTRY 
 
 We must, however, bear in mind that none of these syntheti- 
 cal febrifuges are antiperiodics, and therefore cannot be employed 
 instead of the natural alkaloid quinine in cases of ague or inter- 
 mittent fevers. 
 
 COAL-TAR AROMATIC PERFUMES 
 
 A third group of no less interest comprises the artificial 
 aromatic essences, and of these may here be mentioned, in the 
 first place, cumarin y C 9 H 6 O 2 , the crystalline solid found in the 
 sweet woodruff, in Tonka bean, and in certain sweet-scented 
 grasses. This is now artificially prepared by acting upon sodium 
 salicyl aldehyde with acetic anhydride by the reaction which is 
 associated with the name of Dr Perkin, and is used in the manu- 
 facture of the perfume known as " extract of new-mown hay." 
 
 A second interesting case of a production of a naturally 
 occurring flavour, is the artificial production of vanillin, the 
 crystalline principle of vanilla. Vanilla is the stalk of the Vanilla 
 planifolia, which encloses in its tissues prisms of crystalline vanillin, 
 to which substance it owes its fragrance. Tiemann and Harrmann 
 showed that vanillin is the aldehyde of methyl protocatechuic acid. 
 
 C 6 H 3 (OH)(OCH 8 )CHO. [CHO : OCH 3 : OH = i : 3 : 4]. 
 
 The chief seats of the vanilla productions are on the slopes of 
 the Cordilleras north-west of Vera Cruz in Mexico, also the 
 island of Reunion, and in the Mauritius. Since the discovery of 
 the artificial production of vanillin, the growth of the vanilla has 
 been very much restricted. 
 
 A variety of vanilla, termed vanillon, obtained in the East 
 Indies, has long been used in perfumery for preparing " essence 
 of heliotrope." This contains vanillin together with an oil, which 
 is probably oil of bitter almonds. The essence of white heliotrope 
 is now entirely prepared by synthetical operations. It is manu- 
 factured by adding a small quantity of artificial oil of bitter 
 almonds to a solution of artificial vanillin ; when these substances 
 are allowed to remain for some time in contact, the mixture 
 assumes an odour closely resembling that of natural heliotrope. 
 
VIII. : i886 
 
 THE SCIENTIFIC DEVELOPMENT OF THE 
 COAL-TAR COLOUR INDUSTRY 
 
 BY PROFESSOR R. MELDOLA, F.C.S., F.I.C. 
 
 (Journal of the Society of Arts^ 1886, p. 759) 
 
 IT will, I think, be conceded that the manufacture of coal-tar 
 products is par excellence the most scientific of the chemical in- 
 dustries. This high position may fairly be claimed for the 
 industry when we consider the number and complexity of the 
 products, the delicacy of many of the reactions employed, the 
 special arrangement of plant required, and the intimate knowledge 
 of the chemistry of the aromatic compounds which the colour 
 chemist must at the present time possess. Moreover, the 
 industry is of comparatively recent growth it has been born and 
 has reached its present development within the last thirty years, 
 so that the successive phases of its evolution can be clearly traced. 
 For these reasons the subject is well calculated to throw light 
 upon the general question of technical chemical education, a 
 question of which the importance to the country at large now 
 bids fair to become duly recognised. 
 
 In the brief historical sketch which I now propose to lay 
 before you, I shall mention only those discoveries which may be 
 considered to mark distinct commercial epochs in the develop- 
 ment of the industry. The successive steps in this development 
 will furnish us with one of the most striking illustrations of the 
 utilisation of scientific discovery for industrial purposes, and the 
 reaction of industry upon pure science. 
 
 Commencing in the year 1856, the foundation of the coal-tar 
 colour industry was laid by Perkin, by the discovery of mauve, 
 
 121 
 
122 THE BRITISH COAL-TAR INDUSTRY 
 
 a violet dye, obtained accidentally in the course of an investiga- 
 tion having for its object the preparation of quinine by an artificial 
 synthesis. In 1860, magenta, which had formerly been made in 
 small quantities by expensive processes, was rendered a product 
 of the first order of commercial importance, by the discovery of 
 the arsenic acid process by Medlock and E. C. Nicholson simul- 
 taneously. During this same year, phenylated blues were first 
 produced by Girard and De Laire, by the action of aniline upon 
 a magenta base at a high temperature. These blues had but a 
 limited application owing to their insolubility, and their value 
 was enormously enhanced by Nicholson's discovery in 1862, that 
 these colours could be converted into soluble sulphonic acids. 
 The first azo colour, amido-azobenzene, a basic yellow dye, was 
 introduced in 1863, by the firm of Simpson, Maule & Nicholson, 
 under the name of aniline yellow. In this same year the 
 methylic and ethylic derivatives of magenta were manufactured 
 by the same firm, under the name of Hofmann violets, in 
 honour of their discoverer. Azodiphenyl blue, the first of the 
 colouring matters now known as indulines, and Manchester 
 yellow, appeared in 1864; and in 1866 Bismarck brown 
 (triamidoazobenzene) was first manufactured at Manchester. 
 The same year (1866) was marked by the introduction of 
 Coupler's nitrobenzene process for the manufacture of magenta. 
 In 1868, Graebe and Liebermann gave to the world their great 
 discovery of the chemical constitution of alizarin, and in the 
 following year the manufacture of this colouring matter from 
 anthracene was commenced. The first members of the great 
 family of the " phthalemes," viz. gallem and fluorescem, were 
 discovered by Baeyer in 1871 ; and the first technical application 
 of this discovery was made in 1874 by Caro, who introduced the 
 beautiful pink tetrabromfluorescem into commerce, under the 
 name of eosin. Diamidoazobenzene was discovered by Caro 
 and Witt independently in 1875, and was introduced into com- 
 merce by the latter as chryso'fdine. A great impetus was given 
 to the technical production of azo-colouring matters by this dis- 
 covery, the napthol oranges and other " tropoeolines," fast-red, 
 the ponceau scarlets, etc., appearing in 1878. Methylene blue 
 and acid magenta were introduced by Caro in 1877, an d i n the 
 same year the old and fugitive aniline yellow was converted 
 into a valuable acid yellow by Grassier, who patented a process 
 for converting the base into a sulphonic acid. Malachite green 
 
SCIENTIFIC DEVELOPMENT OF THE INDUSTRY 123 
 
 was introduced in 1878, and in 1879 the first member of the now 
 important group of secondary azo compounds appeared under 
 the name of Biebrich scarlet. It is these secondary azo scarlets, 
 and especially the croceine scarlets (discovered in 1 88 1), which 
 are exterminating the cochineal industry. The year 1880 was 
 marked by the brilliant discovery of the constitution of indigo, 
 and the synthesis of this colouring matter by Baeyer, a discovery 
 which is none the less a triumph of synthetical chemistry because 
 the manufacture is not at present successful from a commercial 
 point of view. Indophenols were introduced by Koechlin and 
 Witt in 1 88 1, and in 1883 appeared Caro's first patent for the 
 production of colouring matters of the rosaniline group by the 
 method of " condensation " with phosgene gas, in the presence of 
 suitable condensing agents. 
 
 This chronological record comprises nearly all the chief 
 colouring matters from coal-tar which are or have been of in- 
 dustrial value. It is important to note that the list, even as it 
 stands in the form of a bald statement of facts in chemical history, 
 reveals the existence of that fundamental law of the " survival of 
 the fittest." Old products have been displaced by newer ones, 
 as fresh discoveries were made, or processes improved, and to 
 the chemist it is of interest to observe how this development of 
 an industry has gone on part passu with the development of the 
 science itself. The moral conveyed to the manufacturer is 
 sufficiently obvious. If we are to recover our former supremacy 
 in this industry, we must begin by dispelling conservative ideas 
 we must realise the fact that no existing process is final, and 
 that no product at present sent into the market is destined to 
 survive for an unlimited period. The scientific manufacturer 
 must be brought to see that present success is no guarantee for 
 future stability, and unless he realises this position in its fullest 
 significance, he may find the sale of his standard products gradu- 
 ally falling off, or be compelled to wake up to the unpleasant fact 
 that his competitors are underselling him, owing to improved 
 methods of manufacture. 
 
 It may appear to many that I am here simply preaching the 
 doctrine of progress, and that the remarks which I have offered 
 are mere truisms. Unfortunately, the facts of the case render 
 this appeal necessary. It must never be forgotten that the coal- 
 tar colour industry is essentially of English origin. It was 
 Faraday who first discovered benzene in 1825 ; it was Mansfield 
 
i2 4 THE BRITISH COAL-TAR INDUSTRY 
 
 who, in 1847, fi rst isolated this substance in large quantities from 
 coal-tar, and showed how nitro-benzene could be manufactured 
 therefrom. The beginning of the colour industry was Perkin's 
 discovery of mauve ; and the introduction of the new colour into 
 dyeing establishments was due to the example set by Messrs 
 Pullar, of Perth, in 1856. The manufacture of magenta on a 
 large scale was the result of the discovery of the arsenic acid 
 process by Medlock and Nicholson ; and the phenylic blues 
 were made commercially valuable by Nicholson. The first azo 
 colours, aniline yellow and Manchester brown, as well as Man- 
 chester yellow (dinitro-a-naphthol), were manufactured in this 
 country. We may thus fairly lay claim to have given to the 
 commercial world the types of all the more important colouring 
 matters of the present time. If, as is certainly the case, the 
 development of these typical products has been allowed to take 
 place in other countries, it behoves us, as a practical nation, to 
 inquire closely into the cause of this success abroad, a success 
 which will appear all the more remarkable when we bear in mind 
 that we are the largest European producers of the raw material, 
 gas tar, out of which the colours are manufactured, as well as 
 being among the largest consumers of the dyes themselves. It 
 is estimated that the amount of tar distilled annually in this 
 country is about 500,000 tons, and it is certain that we distil 
 at least one-half of the whole amount of tar produced in 
 Europe. The present state of affairs is that our competitors 
 can afford to import the raw materials from us, to manufacture 
 and return the colours so as to compete with us successfully in 
 our own markets, and to undersell us in the foreign markets. 
 The bare mention of these facts will be sufficient to indicate 
 the existence of something requiring radical reform in our 
 manufacturing system. 
 
 Before submitting to you the statistics of this industry which 
 I have been able to collect, I think it is desirable to make an 
 attempt to show the inner mechanism by which chemical science 
 has been and is being so successfully adjusted to commercial 
 wants by our Continental neighbours. I regret exceedingly that 
 my predecessors on this and other platforms have not left me 
 the chance of giving a general sketch of the chemical develop- 
 ment of the different groups of colouring matters. In fact, I 
 find myself suffering here from several distinct disadvantages, but 
 I hope, with your forbearance, to make the best of the situation. 
 
SCIENTIFIC DEVELOPMENT OF THE INDUSTRY 125 
 
 It will serve my purpose equally well, or perhaps even better, to 
 confine my illustration to one particular group of colouring 
 matters. The more striking achievements, such as the syntheses 
 of alizarin and indigo, are now so familiar to chemical audiences, 
 that their repetition would be unnecessary. Equally instructive, 
 from the present point of view, would be the history of the 
 colouring matters of the rosaniline group, and I can only express 
 a passing regret that time will not permit me to recapitulate the 
 steps in the beautiful series of investigations which led to the 
 establishment of the structural formula of rosaniline and its 
 derivatives by E. and O. Fischer, and then to the synthesis of 
 these colours by Caro from ketone bases. The principle which I 
 wish to bring out may seem a strange one to a " practical " 
 people, but I am convinced that the whole secret of success abroad 
 is the spirit of complete indifference to immediately successful 
 results in which the researches are carried on. I say, " immedi- 
 ately successful," because it would of course be absurd on the 
 part of an investigator not to take advantage of any discovery 
 which happened to be of commercial value. But, as a general 
 principle, the question of practical utility does not in the first 
 place enter into the work. The great development of this and 
 many other industries is mainly due to the complete and thorough 
 recognition, on the part of our competitors, of the vital import- 
 ance of chemical science. In this country, where the word 
 " practical " threatens to become a reproach, we put science into 
 the background, and attach all importance to the mere technique 
 of our manufactures. If I might venture to offer an aphorism 
 to the English manufacturer, it would be to the effect that he 
 should look after the science, and leave the technique to take care 
 of itself. 
 
 After these considerations, you will see that it is a matter 
 of perfect indifference whether I take by way of illustration 
 products which have been successful from a financial point of 
 view or not. In order to give greater emphasis to the principle, 
 1 propose, however, to consider the history of some colouring 
 matters which have found a market value, and I select this group 
 with the more readiness because, on the one hand, it was not 
 treated of last year by Dr Perkin, and, on the other hand, it 
 furnishes a splendid illustration of the way in which these coal- 
 tar products are being scientifically developed in the foreign 
 laboratories. 
 
126 THE BRITISH COAL-TAR INDUSTRY 
 
 In 1863, Mr E. C. Nicholson discovered a basic orange 
 colouring matter among the by-products formed during the 
 manufacture of magenta by the arsenic acid process. The 
 method of isolating this substance in a state of purity was very 
 skilfully worked out by Messrs Simpson, Maule & Nicholson, 
 and the colour was introduced into the market under the name 
 of phosphine. This dye was the first basic orange discovered, 
 and the advantages which it possessed for certain kinds of dyeing 
 enabled the manufacturers to sell it at a price which helped to 
 cheapen the cost price of magenta to an appreciable extent. The 
 chemical composition of the substance was established in 1863 
 by Hofmann, who assigned the formula C2oHi 7 N 3 . H 2 O, and 
 described the base under the name of chrysaniline. Although 
 other and cheaper basic orange colouring matters have since been 
 discovered, chrysaniline still finds a distinct use ; and I am 
 informed by Messrs Brooke, Simpson & Spiller that the 
 amount of this colour now sold is not appreciably less than at 
 the time of its introduction by their predecessors. The chemical 
 constitution of chrysaniline remained unknown till about two 
 years ago, when the problem was solved by O. Fischer (Ber. y 
 1884, p. 203). In order to be able to follow the steps in the 
 investigation, it will be necessary, in the first place, to go back 
 to the discovery of another colouring matter, called flavaniline, 
 of which the existence was made known by O. Fischer and 
 C. Rudolph in 1882 (Ber., 1882, p. 1500). Flavaniline was 
 produced by the action of dehydrating agents, such as zinc 
 chloride, upon acetanilide, this fact having been observed by 
 Rudolph in i88i,and the practical manufacture of the colour 
 having been carried on under a patent by Messrs Meister, Lucius 
 & Brttning, of the Hoechst colour works. 1 Supplied with a large 
 quantity of the pure crystalline material by the manufacturers, 
 Messrs Fischer and Rudolph established the formula of flavaniline, 
 C 16 H 14 N 2 , and showed that its formation from acetanilide might 
 be expressed by the equation : 
 
 2 C 6 H 5 . NH . C 2 H 3 O - 2OH 2 = C 16 H 14 N 2 . 
 
 By the action of nitrous acid upon flavaniline a diazo compound 
 was produced which, by the usual method of decomposition by 
 water, gave a phenolic derivative termed flavenol, possessing 
 
 1 I am indebted to this firm for having kindly supplied me with specimens 
 of these products for exhibition. 
 
SCIENTIFIC DEVELOPMENT OF THE INDUSTRY 127 
 
 the formula C 16 H 12 N . OH, thus proving that flavaniline con- 
 tained a displaceable NH group. By heating flavenol with zinc 
 dust, a base was obtained having the formula C 16 H 13 N, and 
 termed flavoline. This base had an odour resembling that of 
 quinoline, and all its properties suggested to the authors that 
 flavaniline was in reality a quinoline derivative. That flavaniline 
 was amido-flavoline was proved by nitrating the latter base, and 
 reducing the nitro compound, when flavaniline was obtained. 
 In a later publication by Besthorn and Fischer (Ber. y 1883, p. 
 68) it was announced that flavenol, when oxidised by potassium 
 permanganate in an alkaline solution, gave an acid which, on 
 distilling with lime, furnished a base having all the characters of 
 lepidine. By the continued oxidation of flavenol with excess of 
 alkaline permanganate, another acid was obtained, which proved 
 to be picoline-tricarbonic acid, and the latter, on further oxidation, 
 gave picoline-tetracarbonic acid (Eer.^ 1884, p. 2925). 
 
 So much for the facts ; now for their interpretation. The 
 production of flavenol from flavaniline by the diazo reaction 
 shows that the respective formulas of these substances are : 
 
 C 16 H 12 (NH 2 )N C 16 H 12 (OH)N. 
 
 Flavenol gave, as the first product of oxidation, lepidine- 
 carbonic acid, of which the formula is Ci H 8 N(CO 2 H), and by 
 further oxidation it gave picoline-tricarbonic acid, of which the 
 formula is C 6 H 4 N(CO 2 H) 3 . Now the C-atoms oxidised by the 
 breaking down of the 1 6 -carbon atom flavenol into n -carbon 
 atom lepidine-carbonic acid, are those C-atoms which in flavenol 
 are associated with the hydroxyl group, because this group is no 
 longer contained in the product of oxidation. Thus the formulas 
 of flavaniline, flavenol, and flavoline are better expressed as : 
 
 C 10 H 8 N . C 6 H 4 (NH 2 ) 
 
 C 10 H 8 N.C 6 H 4 (OH) 
 
 C 10 H 8 N.C 6 H 5 . 
 
 From this it appears that flavanaline is amidophenyl-lepidine, 
 flavenol hydroxyphenyl-lepidine, and that flavoline is phenyl- 
 lepidine. 
 
 The central nucleus of flavaniline having thus been shown to 
 be lepidine (which is methylquinoline), the next question to 
 be settled was the mode of formation of the colour base from 
 acetanilide. The authors suggest that at the high temperature 
 
128 THE BRITISH COAL-TAR INDUSTRY 
 
 of the reaction, acetanilide, in the first place, becomes transformed 
 into the isometric orthoamidoacetophenone : 
 
 CH 3 
 ? Hs rn/ C:0 
 
 ^6 H 4< 
 
 C 6 H 5 .NH.C:0 X NH 2 
 
 Acetanilide. Amidoacetophenone. 
 
 By the condensation of two molecules of the amidoaceto- 
 phenone with the elimination of two molecules of water, flav- 
 aniline would be produced in a manner analogous to the 
 formation of mesitylene by the condensation of three molecules 
 of acetone under the influence of dehydrating agents : 
 
 CH 3 CH 3 
 
 / 
 C 6 H 4 <( | =C 6 H 4 < | 
 
 \N = |H 2 Oi = C - C 6 H 4 . NH 2 \N = C - C 6 H 4 . NH 2 
 
 The accuracy of this suggestion was verified by showing that 
 orthoamidoacetophenone is present in small quantity when the 
 reaction is arrested as soon as the formation of colouring matter 
 commences ; and conversely, when pure orthoamidoacetophenone 
 was heated with zinc chloride, flavaniline was produced in small 
 quantity. 
 
 We may be permitted to pause at this stage of the investiga- 
 tion before proceeding to consider the connection of this work 
 with the constitution of chrysaniline. These results cannot but 
 be regarded by chemists as a very beautiful piece of investigation ; 
 but the person of a " practical " turn of mind may possibly want 
 to know what bearing they have upon the question of market 
 value the question which the manufacturer but too frequently 
 considers as the only one of importance. Now, it is the essence 
 of chemical science as indeed of all other sciences that every 
 discovered fact is related to other groups of facts, and, although 
 the relationship may not at once be apparent, it is only a matter 
 of further development that is necessary in order to reveal 
 relationships which are obscure on account of our imperfect 
 knowledge. Thus the policy of looking at a chemical product 
 from the narrow point of view of immediate utility is not only 
 unscientific, but it is detrimental to the interests of the manu- 
 
SCIENTIFIC DEVELOPMENT OF THE INDUSTRY 129 
 
 facturer himself. Every new compound or process discovered 
 every structural formula established by legitimate investigation 
 may have an enormous influence, directly or indirectly, upon the 
 market value of products at present sent into commerce. Our 
 manufacturers must realise this if they wish to recover their 
 position in the coal-tar industry, or in fact in any other chemical 
 industry. There is no branch of manufacture so perfect as not 
 to be open to further improvement, and until the broad spirit of 
 scientific development is made to replace the suicidal policy of 
 immediate utility, our position as a manufacturing nation is not 
 likely to be improved. 
 
 In order to justify this digression by the particular instance 
 now under consideration, we must return to the work of Messrs 
 Fischer and Besthorn. The discovery that flavaniline was a 
 quinoline derivative was of importance as a principle, quite apart 
 from any immediate value attaching to the dyestuff itself . Up 
 to the time of this discovery, the quinoline derivatives had been 
 practically of no importance in the tinctorial industries, but as a 
 consequence of the present investigation the question at once 
 suggested itself whether the analogous bases of high boiling-point, 
 which are present in coal-tar, such, for example, as acridine, 
 might not be utilised as sources of colouring matters. I may 
 remind you that the fact of quinoline being an aromatic compound 
 was first established by the researches of our Chairman this 
 evening, Professor Dewar, who obtained aniline from this base. 
 In a subsequent paper on chrysaniline (O. Fischer and G. KSrner, 
 Ber., 1884, p. 203), it was pointed out that in the course 
 of his investigations upon rosaniline Fischer had observed that 
 the former base, like rosaniline, was capable of furnishing a 
 diazo compound. An observation made by Claus is also men- 
 tioned, viz. the conversion of chrysaniline into a phenol (chryso- 
 phenol) by heating to a high temperature with hydrochloric acid 
 in accordance with the equation : 
 
 C 16 H 15 N 3 . HC1 + H 2 = C 19 H 15 N 2 + NH 4 C1 
 
 Chrysaniline hydrochloride. Chrysophenol. 
 
 The investigation of flavaniline appears to have given an 
 impetus to the ideas respecting chrysaniline, because of the 
 general similarity in the properties of these two substances. In 
 confirmation of this impression, it was found that by the oxida- 
 tion of chrysophenol an acid was obtained which, on distillation 
 
 9 
 
130 THE BRITISH COAL-TAR INDUSTRY 
 
 with lime, gave a pyridine base. I need hardly remind you 
 that picoline, which was obtained from the acid resulting from 
 the extreme oxidation of flavenol, is methylpyridine. It was 
 thus established that chrysaniline was a derivative of a quinoline 
 base. 
 
 The next step in the investigation is a very important one. 
 By decomposing the diazo compound of chrysaniline with 
 alcohol according to the Griess reaction, phenylacridine was 
 obtained. Acridine is a base belonging to the quinoline series, 
 having the formula C 13 H 9 N. It was discovered by Graebe and 
 Caro in 1872 in crude anthracene. Phenylacridine accordingly 
 possesses the formula Ci 3 H 8 N . C 6 H 5 ; and chrysaniline appears 
 as diamidophenylacridine Ci3H 7 (NH 2 )N . C 6 H 4 (NH 2 ), because 
 two amido groups are replaced by H by the diazo reaction. 
 Thus the formula C 2 oH 17 N 3 (first assigned by Hofmann to 
 chrysaniline) is really the formula of the higher homologue, 
 chrysotoluidine. 
 
 In order to explain the formation of chrysaniline during the 
 oxidation of the materials (aniline and toluidine) in the " red 
 melt " still, several suggestions were put forward, of which the 
 most probable appeared to be that the base was derived from 
 triamidotriphenylmethane, the latter compound resulting from 
 the condensation of two molecules of aniline with one of ortho- 
 toluidine : 
 
 /NH 2 
 C 6 H/ + 2C 6 H 5 . NH 2 - 2H 2 = HC(C 6 H 4 NH 2 ) 3 
 
 C^Hg Triamidotriphenyl- 
 
 methane. 
 
 /Ni H 2 /Nv 
 
 C 6 H/ =C 6 H 4 < | >C 6 H 3 .NH 2 
 
 \CH.HjC 6 H 3 .NH 2 -2H 2 \C/ 
 
 I' C 6 H 4 .NH 2 
 
 C 6 H 4 .NH 2 
 
 Triamidotriphenylmethane. Diamidophenylacridine 
 
 = Chrysaniline. 
 
 The relationship of chrysaniline to the colouring matters of 
 the rosaniline group is thus indicated ; but, tempting as is this 
 theme, time will not admit of further digression into this field. 
 The main point, so far as we are at present concerned, is that 
 by means of the present investigation we have now arrived at 
 a knowledge of the parent substance, acridine, of which a 
 colouring matter more than twenty years old proves to be a 
 
SCIENTIFIC DEVELOPMENT OF THE INDUSTRY 131 
 
 derivative. By such results new fields of investigation are 
 opened up, and direct methods for the production of chrysaniline 
 suggest themselves. Even the practical requirements would be 
 satisfied if it could be shown that the colour could be manu- 
 factured cheaply by a direct synthesis, instead of depending, as 
 heretofore, upon the small and capricious secondary product of 
 the magenta manufacture. As a matter of fact, several syntheses 
 of chrysaniline have been effected, one of which forms the sub- 
 ject of a patent (German patent, 29142, April 1884) by Messrs 
 Ewer & Pick, of Berlin. Into the mode of preparation by 
 this patented process I cannot now enter any further than by 
 merely stating that nitrodiphenylamine and nitrobenzoylchloride 
 form the starting-points, and that the specification bears the 
 title, " preparation of chrysaniline and other colouring matters 
 of the phenylacridine group." If an elaborate scientific in- 
 vestigation culminates in a patent, its utility will, I know, be 
 conceded by many for whom the work would otherwise have 
 possessed no particular interest. 
 
 The illustration which I have given is a typical example of 
 the kind of scientific development which is being carried on by 
 our chemical colleagues abroad, and which is being taken ad- 
 vantage of in the Continental factories. I do not wish to give 
 you the impression that the particular colouring matters dealt 
 with are of supreme importance industrially they are of con- 
 siderable importance, but the modern history of any other 
 colouring matters would have been equally instructive. The 
 beautiful researches of Bernthsen upon the constitution of 
 methylene blue would have done equally well had time per- 
 mitted of my making use of them. 
 
 It was stated at the commencement of this paper that there 
 is reason to believe that our supremacy in the coal-tar colour 
 industry has, for some years, been declining, and I have further 
 expressed my belief that the chief cause of this falling off is the 
 subordinate position given to chemical science in this country as 
 compared with the status of this science abroad. Whether this 
 explanation be accepted or not, the fact of the decadence of the 
 manufacture remains, and I am in a position to bring this un- 
 pleasant truth home to our countrymen by a strong body of 
 evidence. It must be borne in mind that the decline of any 
 industry cannot be measured by the absolute weight of the 
 products turned out annually, because the demand for the pro- 
 
1 32 THE BRITISH COAL-TAR INDUSTRY 
 
 ducts in question may be on the increase, and we may be 
 actually producing a greater weight of colours now than we 
 were during our most successful period. The whole question 
 is a relative one : it is simply, how much material are we now 
 turning out as compared with the amount produced by our 
 competitors what proportion of coal-tar products do we supply 
 for our own and foreign consumption ? In order to answer 
 this question with some approach to numerical exactness, it 
 occurred to me that the most trustworthy information could 
 be obtained from the consumers themselves ; and through the 
 kindness of Mr Robert Pullar, of Perth, and Mr Ernest 
 Hickson, of Bradford, I have been enabled to put myself into 
 communication with several of the representative dyeing and 
 printing establishments of this country. The facts obtained, as 
 showing the actual state of the industry at the present time, 
 appear to me of sufficient interest to be given here in some 
 detail. I may take the present opportunity of stating that my 
 application for statistical information has been most courteously 
 responded to by the various firms, to whom I have great 
 pleasure in returning my thanks. 
 
 Edward Ripley & Son, of Bradford, perhaps the largest 
 dyers of piece goods in the kingdom, inform me that during the 
 year 1885 they used 86J per cent, of foreign coal-tar colours, 
 and 13^ per cent, of English make. 
 
 Walter Walker & Son, of Dewsbury, dyers of wool for 
 rugs, mats, carpet yarn, and blanket stripes, estimate that during 
 1885 they used 80 per cent, of German dyes. They state that 
 the exact proportion is difficult to estimate, so that the figure 
 given is only approximative. Referring to their larger con- 
 sumption of foreign colour, they state : " It is very discouraging 
 to have to do this and send the trade out of our country, but 
 to our own interest and advantage we have to do it." 
 
 John Newton, silk dyer, Macclesfield. Mr Walter Newton, 
 F.C.S., informs me that during 1885 they used 80 per cent, of 
 foreign colour. He adds : " The rapid advancement in the 
 improved manufacture of some of these dyes by the Germans 
 is the only cause of our desertion from the English colour 
 manufacturer." 
 
 G. W. Oldham, silk dyer, of Netherton, near Huddersfield, 
 informs me that during 1885 he used 2000 Ibs. of German dyes, 
 1 100 Ibs. of English dyes, and 800 Ibs. of doubtful origin. 
 
SCIENTIFIC DEVELOPMENT OF THE INDUSTRY 133 
 
 James Templeton & Co., of Glasgow, state that they dye 
 as much as 30,000 Ibs. of yarn (chiefly worsted) weekly, but 
 they use only a small proportion of coal-tar dyes, all of which 
 are of German manufacture. 
 
 Messrs Leckie & MacGregor, of Paisley, inform me 
 that in the west of Scotland, including Glasgow and Paisley, 
 they are certain that at least 90 per cent, of the dyes used come 
 from the Continent. Their own consumption of English colour 
 only reached 6*8 per cent. 
 
 Alexander Harvey & Son, of Glasgow, yarn dyers, state 
 that during 1885 they used 60 per cent, of German and 40 per 
 cent, of English dyes. These figures do not include alizarin, of 
 which they state that they used about equal quantities of 
 German and English make. The English supply is chiefly 
 made up of one article, " aniline salt." They add : " We find 
 the German makes in general of better value than the British, as 
 our rule is, ceteris paribus, to give the home-make the preference." 
 
 Messrs Manson & Henry, Glasgow, yarn dyers, state that 
 they use only German dyes, adding that they find it to their 
 advantage "for both cheapness and quality." 
 
 Among the largest consumers of coal-tar colours in this 
 country are the jute dyers. As representing this department of the 
 tinctorial industry, Messrs James Stevenson, of Dundee, inform 
 me that during 1885 they used only 7*7 per cent, of English 
 colour. They have been good enough to supply the following 
 analysis of their consumption : 
 
 per cent., of which nothing is English. 
 
 6-4 
 nothing 
 
 nothing 
 
 Scarlet . 
 
 
 37 perc 
 
 Crimson 
 
 
 16 
 
 Blues . 
 
 
 ii-5 
 
 Oranges 
 
 
 ii 
 
 Greens . 
 
 
 7 
 
 Magenta (resi 
 
 dues) 
 
 6 *5 
 
 Maroon 
 
 
 
 5'5 
 
 Pink 
 
 
 
 2-75 
 
 Brown 
 
 
 
 I>2 5 
 
 Violet 
 
 
 
 i 
 
 Various 
 
 
 
 'S 
 
 100*0 
 
 1-25 
 
 nothing 
 
 77 
 
 Messrs Cox Bros., of the Camperdown Jute Works, Lochee, 
 state that practically the whole of the " aniline " colours used by 
 them are of Continental manufacture. 
 
134 THE BRITISH COAL-TAR INDUSTRY 
 
 With reference to the calico-printers, the following facts have 
 been collected : 
 
 Messrs Z. Heys & Sons, of Barrhead, state that during 
 1885 they used over 10,000 Ibs. weight of colours (exclusive of 
 alizarin), of which 700 Ibs. only were of English make. 
 
 Messrs James Black & Co., of Bonhill, Dumbartonshire, 
 state that in their belief more than one-half of the colour used 
 by calico-printers is of foreign manufacture. 
 
 In the course of the present inquiry it seemed desirable to 
 obtain information concerning the consumption of alizarin, with 
 reference to which the following statements have been received : 
 
 O 
 
 Messrs Walter Crum & Co., of Thornliebank, Glasgow, are 
 of opinion that " the great bulk of what is used in this country 
 is manufactured in Germany." They do not profess to be able 
 to give actual figures having any approach to accuracy. 
 
 Mr John Christie, of the Alexandria Turkey-Red Works, 
 Dumbartonshire (John Orr-Ewing & Co.), states that they use 
 only artificial alizarin in their establishment, their consumption 
 being considerably over two million Ibs. weight of 10 per cent, 
 paste annually. Their consumption was in 
 
 1880 . 98 per cent. German. 2 per cent. English. 
 
 9 ?> * j 
 
 100 o 
 
 1881 . 
 
 1882 . 
 
 1883 . 
 
 1884 . 
 
 1885 . 
 
 77 2 3 
 
 5 6 i ' 44 
 
 47 >, 53 
 
 
 Messrs William Stirling & Sons, of Glasgow, state that 
 their relative consumption of English and German alizarin for 
 Turkey-red dyeing varies so much from year to year that they 
 have no means of directly supplying useful data. This firm has, 
 however, been good enough to make inquiries for me from a 
 competent authority, who has furnished the following report : 
 
 "In 1883 and 1884, I estimate that the sales (of alizarin) in 
 the United Kingdom amounted to a monthly average of about 
 530 tons, 10 per cent, (say, 6360 tons, 10 per cent, per annum). 
 Of this quantity, I estimate about 30-33 per cent, was manu- 
 factured in this country. Taking 1884 alone, the figures are 
 estimated at 566 tons, 10 per cent, per month (say, 6800 tons, 
 10 per cent, per annum). Proportion manufactured in Great 
 Britain, say, about 30-35 per cent. In 1886, the consumption 
 may be estimated at 550-600 tons, 10 per cent, per month (say, 
 
SCIENTIFIC DEVELOPMENT OF THE INDUSTRY 135 
 
 6900 tons, 10 per cent, per annum). Proportion manufactured 
 in this country probably now very considerably more than 
 35 per cent." 
 
 This estimate of the total consumption (550 600 tons, 
 10 per cent, per month) is confirmed by my friend Mr Thomas 
 Royle, F.C.S., of the British Alizarin Company's works at 
 Silvertown, but he is of opinion that 50 per cent, of this is of 
 English manufacture. 
 
 By way of further confirmation, it appeared to me to be 
 desirable to get the opinion of manufacturers themselves, and 
 although this has been a matter of considerable difficulty, I am 
 able to give some kind of an estimate. Mr Ivan Levinstein, of 
 Manchester, estimates that Germany produces : 
 
 Colours derived from benzene and toluene, six times more 
 than England. 
 
 Colours derived from naphthalene, seven times more than 
 England. 
 
 Colours derived from anthracene, five times more than 
 England. 
 
 The average production of Germany is thus about six times 
 that of this country. Mr W. A. Mitchell, of the firm of W. C. 
 Barnes & Co., Phoenix Works, Hackney Wick, informs me that 
 of some 159 tons of "aniline" dyes which passed through their 
 hands as agents last year, 95 per cent, were of Continental make. 
 With reference to the two chief raw materials, benzene and 
 aniline, this same firm estimates that about 75 per cent, of the 
 whole quantity of these products made in England goes to the 
 Continent. 1 
 
 The facts and figures which I have now laid before you must 
 be left to tell their own story time will not permit me to 
 attempt any analysis of them. The evidence collected will at 
 any rate give a much more forcible idea of the true state of 
 the coal-tar colour industry in this country than has hitherto 
 been attempted, and if this evidence goes against us as a 
 manufacturing nation, it is all the more desirable that our true 
 
 1 According to a later estimate, kindly supplied by Mr Ivan Levinstein 
 the quantity of benzene and toluene used in this country amounts to about 
 half a million gallons, and that used in Germany to about two million 
 gallons annually. About half the English production is, however, exported 
 as aniline, toluidine, and aniline salt, while Germany converts into colouring 
 matters at least 1,600,000 gallons of these hydrocarbons. 
 
136 THE BRITISH COAL-TAR INDUSTRY 
 
 position should be realised. I find that it is almost impossible 
 to give a correct numerical expression in pounds sterling for 
 the annual value of this industry to the country, as the estimates 
 vary within very wide limits. According to Dr Perkin, whose 
 opinion on this matter will perhaps carry the greatest weight, 
 the value of the annual output is between ^3,000,000 and 
 ^4,000,000. That the industry is one of considerable import- 
 ance on the Continent may be gathered from the official returns 
 relating to the German exports. For the following figures 1 
 am indebted to Dr H. Caro, of the Badische Anilin- und 
 Soda-Fabrik, Ludwigshafen on Rhine : 
 
 EXPORTED FROM GERMANY, FROM JANUARY i TO DECEMBER 31, 1885. 
 
 Alizarin paste (? per cent.) . . . 4283 tons. 
 Aniline and intermediate products . . 1713 
 Aniline, etc., colours .... 4645 
 
 Dr Caro adds that it is generally believed that about four- 
 fifths of the entire German production are exported. 
 
 The magnitude of this branch of chemical industry abroad 
 will be gathered from the fact that a German factory of about 
 the third magnitude consumes at the present time between 500 
 and 600 tons of aniline annually. According to information 
 recently furnished to me from the two largest of the German 
 factories, the Badische Company employ 2500 working men and 
 officials, and the Hoechst Colour Works (formerly Meister, 
 Lucius & Brttning) 1600 working men and fifty-four chemists. 
 It must of course be borne in mind that in these factories the 
 products are not "aniline" colours only, but alizarin, acids, 
 alkalies, and all chemicals required in this branch of manufacture. 
 
 The industry which has been selected for this evening's topic 
 is thus not only an important one in itself, but for us, as 
 chemists, its development is fraught with meaning both scienti- 
 fically and educationally. In taking up this subject it has not 
 been my desire to exalt the coal-tar colour industry to a position 
 of undue importance, nor do I wish it to be inferred that the 
 remarks which I have made concerning its decadence, or at any 
 rate stagnation, in this country are applicable to this manu- 
 facture only. The failure on our part to grasp the true spirit 
 of chemical science in its relation to our manufactures makes 
 itself felt in every industry in which chemistry is concerned. 
 The strength of our competitors is in their laboratories, and 
 
SCIENTIFIC DEVELOPMENT OF THE INDUSTRY 137 
 
 not, as here, upon the exchanges. It is only by showing up 
 our weakness in each industry that the state of affairs can be 
 remedied, and our prestige as a manufacturing country restored. 
 If each specialist would do for his industry what I have here 
 attempted to do broadly for the coal-tar colour industry, we 
 should get together a body of evidence which the Royal Com- 
 missioners on the depression of trade would do well to take into 
 consideration. We have heard a great deal of late years about 
 the subject of technical education, but the talk has been rather 
 one-sided. We have had utterances from those who, recognising 
 the enormous importance of this subject to the country, have 
 munificently endowed those institutions for the promotion of 
 technical education which are springing up around us ; we have 
 had all kinds of schemes from those who are taking upon them- 
 selves the duties of technical educators ; but it appears to me 
 that we have not heard with sufficient distinctness the voices of 
 those who may be presumed to suffer most from the want of 
 technical education, viz. the manufacturers themselves. I have 
 heard rumours of the existence of a certain class of manufacturer 
 let us hope a rare species who declares that science is no use 
 to him, and that he can get along better without it. I must 
 confess that I never met this individual in the flesh, but I know 
 that he exists in some of our manufacturing centres. As a 
 species he is, however, doomed to extinction in the struggle 
 with his competitors, and we may consider him out of court in 
 the discussion of schemes of technical Education. It is now 
 generally admitted that the days of empiricism have passed 
 away, and most manufacturers admit that present success and 
 future development depend upon a proper recognition of 
 technical, i.e. of applied, science. But unless the manufacturers 
 themselves speak loudly on this question, the voices of those 
 who wish to promote scientific education may be drowned by 
 the clamour of mere theorists. 
 
 In no other department of our manufactures is the want of 
 technical science more felt than in the chemical industries. We 
 not only see this in the greater development of these industries 
 abroad, but in some of our most successful factories here and 
 this applies more especially to the coal-tar colour industry 
 foreign chemists are employed, and, as I have lately been informed 
 by a well-known manufacturer, it is even impossible to get the 
 necessary plant properly made in this country. There is no 
 
138 THE BRITISH COAL-TAR INDUSTRY 
 
 doubt that the recondite character of the truths of chemical 
 science, as compared with the more obvious truths of mechanics 
 and physics, has much to do with the want of popularity of this 
 branch of knowledge, and is responsible for the circumstance 
 that our science is regarded with comparative indifference until 
 some branch of manufacture is in extremis. In our national 
 characteristic of being " practical," we are apt to become short- 
 sighted in our manufacturing policy, and to recognise only 
 actualities to the exclusion of the potentiality conferred upon a 
 nation by a broader scientific culture. 
 
 DISCUSSION 
 
 Mr R. J. FRISWELL said, the great difficulty scientific men had 
 to encounter was to persuade those whose money interest placed 
 them at the head of large factories that scientific work, the practi- 
 cal outcome of which was not immediately visible, was really of 
 value. It was a long struggle, but he thought they were 
 beginning to see daylight at last. A feeling was beginning to 
 be awakened, not in the coal-tar colour industry alone, but in 
 others also, and he thought the coming generation of manu- 
 facturers would take to heart the lesson which Professor Meldola 
 and others had so strongly enforced, so that in the course of a 
 few years a great change would be seen in this direction. What 
 had been said with regard to the alizarin industry showed that 
 already in that direction a very marked change was beginning to 
 take place, and he hoped it would not be many years before they 
 saw a change in the same direction in other coal-tar colours. 
 Every Englishman must feel that it was a great reproach to this 
 country that an industry which originated here should so far 
 have slipped out of her grasp. 
 
 The Chairman (Professor JAMES DEWAR) said he desired most 
 heartily to thank Professor Meldola because he had not in any 
 way feared to tell the whole truth. When such a statement 
 came from a man who had not confined himself purely to the 
 scientific side of the question, but who had been himself superior 
 chemist in a large works, it showed that he was, from his thorough 
 knowledge of both sides of the question, entitled to speak in this 
 bold and straightforward way. He must differ from the writer 
 of the paper on one point, where he said he had never met the 
 manufacturer who declined to say that science was a great bene- 
 
SCIENTIFIC DEVELOPMENT OF THE INDUSTRY 139 
 
 factor. On two occasions in his life he had certainly had this 
 experience. At one time, when a young man, he was offered 
 the same position that Professor Meldola held for several years, 
 and the difficulty which arose was entirely with reference to 
 supplying the laboratory. On another occasion a similar diffi- 
 culty arose with a very distinguished man, in which he projected 
 something of the same kind, but the moment he began to ask 
 where the materials were, and where the laboratory was, the 
 engagement was abruptly broken off, as this gentleman saw no 
 reason for having a laboratory in connection with the work at 
 all. There was the difference. It was not only the stimulus in 
 the large German laboratories, where active research was going 
 on, but it was the large stimulus now existent among the factories 
 themselves. There the men were not isolated, but, as they had 
 heard, there were something like fifty chemists in one large 
 factory, so that there was a little scientific world in itself, where 
 there was an incentive to continuous work. With reference to 
 the question as to the want of popularity in chemical science, he 
 admitted it, of course, but the question was, what was the full 
 explanation of it ? He thought it arose in a great degree from 
 the want of encouragement of chemistry in the older universities. 
 He said so, not because the older universities sent out a larger 
 number of men than the young ones, but simply because up to 
 the present time they had no such thing as even a creditable 
 chemical laboratory. Although he held the chair in one of these 
 universities, he was always ashamed if anyone asked to see the 
 chemical laboratory, because, in truth, there was none. It was 
 in the same condition as it was a century ago. If you got a pupil 
 out of the mass who showed some originality, you found you 
 could not retain him, you had not the materials or the money, 
 and consequently he went to some large German laboratory where 
 material was to be had, and where his work was encouraged. As 
 long as that went on, how could the science be popular ? Another 
 important point in the paper was the proof of the marvellous 
 result of action and reaction. Of course, as a physical principle, 
 that was admitted on all hands to be an elementary truth, but all 
 these facts now brought forward had had the most remarkable 
 effect as a stimulus on the growth of ; the more recondite scientific 
 investigation ; every new success connected with any colour which 
 might be discovered was a stimulus to further investigation, and 
 the result was that all the marvellous group of colouring matters 
 
140 THE BRITISH COAL-TAR INDUSTRY 
 
 were now to be had in such enormous quantity that the chemist 
 got numerous new foci from which to start fresh investigations. 
 Consequently, all this industry had conversely affected chemical 
 laboratories, purely scientific, by the supply of splendid new 
 material. 
 
 Mr LIGGINS said it was impossible to overestimate the 
 brilliancy and beauty of these coal-tar dyes, or to give too much 
 praise to those chemists who had invented the processes which 
 had given such brilliant results, and as an artist he must say 
 it was impossible, either with oil or water-colour, to produce 
 colours of such beautiful shades as some of those which were 
 exhibited ; but there were two sides to every question, and 
 several times within the last few weeks the most thorough con- 
 demnation of aniline dyes had been pronounced in that room 
 by able men and scientific men, especially in connection with 
 the artistic work of Japan and India. The carpets of India 
 were said to be ruined by aniline colours which were used in 
 dyeing, and it was said to be one of the greatest misfortunes for 
 India that these colours had been introduced, as they were very 
 inferior to those the natives had been for centuries in the habit 
 of using ; besides that, it was very commonly supposed that the 
 colouring matters of various articles of clothing were poisonous. 
 
 Professor MELDOLA said, with regard to the fugitiveness of 
 these colours, there was a great deal of misapprehension, and the 
 same with regard to the poisonous character of the dyes. A 
 great controversy had been carried on lately in Bradford before 
 the Society of Dyers and Colourists. Specimens had been sub- 
 mitted to careful analysis, in order to detect arsenic, because it 
 was known that some of these colours were made by means of 
 arsenic acid, and it was thought they might retain traces which 
 rendered them poisonous ; but the amount found was infinitesi- 
 mal. No doubt many of these colours were fugitive, but, on the 
 other hand, some of the alizarin colours, which were used for 
 dyeing carpet yarn, would bear exposure to light, and remain 
 unaltered long after the old vegetable colours had faded com- 
 pletely away. 
 
IX.: i8 9 6 
 
 THE ORIGIN OF THE COAL-TAR COLOUR 
 
 INDUSTRY, AND THE CONTRIBUTIONS OF 
 
 HOFMANN AND HIS PUPILS 
 
 BY W. H. PERKIN, PH.D., D.C.L., F.R.S. 
 
 (Hofmann Memorial Lecture : Journal of the Chemical Society^ 1896, p. 596) 
 
 THE illustrious man whose lifework we are called on to com- 
 memorate was well known to very many of us, especially those 
 who had the privilege of being his students and assistants. We 
 can all recall the pleasure and interest with which we listened to 
 the lucid and graphic accounts of his researches which he used 
 to bring before the Chemical Society in years gone by ; and 
 great was felt to be the loss, not only to us, but also to the 
 country, when he left it for his fatherland : but now we mourn 
 a far greater loss, and one which we realise more and more 
 deeply as we consider the incidents of his remarkable career a 
 career of such incessant activity and brilliant achievement. 
 
 I am charged with a duty which I wish had been placed in 
 more capable hands than mine : to give an account of the rise 
 and progress of the coal-tar colour industry, and its relation to 
 the Hofmann school ; and, as being connected with its com- 
 mencement, I am requested to make the account to a large 
 extent autobiographical a part of my task which it would have 
 been more agreeable to me to have seen undertaken by others 
 rather than myself. 
 
 This industry holds an unique position in the history of 
 chemical industries, as it was entirely the outcome of scientific 
 research. We have to go back to 1825, when Faraday discovered 
 benzene, or, as he then termed it " bicarburetted hydrogen," for 
 the first investigation which clearly bears upon the subject. 
 
 141 
 
i 4 2 THE BRITISH COAL-TAR INDUSTRY 
 
 Faraday separated the hydrocarbon from the liquid products 
 condensed on compressing the gas obtained from oil. A year 
 later (1826), Unverdorben obtained aniline by the mere distilla- 
 tion of indigo, and called it " crystalline." Runge afterwards 
 obtained it from coal-tar oil, and having observed that it produced 
 a violet-blue coloration with chloride of lime, called it " kyanol." 
 It was subsequently obtained from indigo by Fritsche by distilling 
 this colouring matter with caustic alkali. We then come to the 
 important work of Mitscherlich, who obtained the hydrocarbon 
 benzene from a new source, namely, benzoic acid, whence the 
 name, and produced from this nitrobenzene. Zinin subsequently 
 found that benzidam, as he termed it, could be produced by the 
 action of sulphuretted hydrogen in presence of ammonia on an 
 alcoholic solution of nitrobenzene. 
 
 This brings us to the commencement of Hofmann's researches 
 on aniline, a substance which he used sometimes to speak of as his 
 " first love." In his first published paper he showed that Unver- 
 dorben's crystalline, Runge's kyanol, Fritsche's aniline, and Zinin's 
 benzidam were all the same compound, for which he afterwards 
 selected Fritsche's name, aniline. Later on, Hofmann and 
 Muspratt prepared toluidine from toluene from tolu balsam. 
 
 The work on the separation of aniline from tar was done 
 before the date of Hofmann's coming to this country, viz. in 
 1 843. After his arrival here in 1 845, he continued his researches, 
 and, to realise something of his indomitable perseverance, it is 
 necessary to remember that, until the coal-tar colour industry 
 was established, practically all the aniline he used in his numerous 
 inquiries was procured by the laborious and costly process of 
 distilling indigo with potash. 
 
 In 1843, organic chemistry was still in its infancy, and coal- 
 tar naphtha had not yet been investigated. Runge had isolated 
 carbolic acid, pyrrol, kyanol or aniline, and leucol or quinoline. 
 Naphthalene was well known to exist in tar, having been separated 
 by Garden, as early as 1820. Dumas had discovered para- 
 naphthalene or anthracene, and chrysene and pyrene had been 
 referred to by Laurent, but these were very doubtful compounds. 
 This was about all that was known of the composition of coal-tar 
 at that time. Hofmann showed, in 1845, tnat benzene must 
 exist in the naphtha, as he found that aniline could be produced 
 from it, but he never separated this hydrocarbon ; shortly after- 
 wards, however, he induced his pupil, Charles Mansfield of 
 
HOFMANN MEMORIAL LECTURE 143 
 
 whom he always spoke in the highest terms to undertake the 
 investigation of the liquid hydrocarbons of coal-tar. 
 
 On reading over the account of Mansfield's investigation, 
 and bearing in mind that in those days fractional distillation was 
 conducted in old-fashioned glass retorts with the thermometer in 
 the liquid, it is impossible not to admire the patience and per- 
 severance he exercised, as well as the systematic and skilful 
 manner in which he worked. 
 
 All who have undertaken fractional distillations, even with all 
 our present knowledge and improved apparatus, know how diffi- 
 cult it is to detect and isolate products in a mixture such as coal- 
 tar naphtha. Yet Mansfield obtained benzene in a pure state, and 
 toluene sufficiently so for Hofmann to prepare toluidine from it. 
 He also obtained pseudocumene, and was led to believe in the exist- 
 ence of xylene. In describing his work, he modestly remarks : 
 
 " It has been perhaps the tedium of the methods necessary to 
 effect a separation of mixed hydrocarbons from each other which 
 has deterred experienced chemists from devoting their time to 
 disentangling the oils here treated off: and perhaps to have con- 
 ducted the innumerable distillations necessary for this purpose 
 in a laboratory imperfectly furnished with gas and other con- 
 veniences, would have been a task too laborious to have been 
 persisted in " (Jour. Chem. Soc., 1849, 1> 246). 
 
 Amongst the inquiries carried on by Hofmann, in the early 
 days of the Royal College of Chemistry, were those classical 
 " researches regarding the molecular constitution of the volatile 
 organic bases," in which he succeeded in displacing the hydrogen 
 of the NH 2 group by different alcohol radicles, eventually ob- 
 taining also the ammonium compounds. In the first of these 
 (Jour. Chem. Soc., 3, 1851) he describes ethylaniline (p. 284), and 
 diethylaniline (p. 288), also methylaniline (p. 295). The method 
 used in these researches, of substituting hydrogen in amines by 
 means of the iodides and bromides of the alcohol radicles, and 
 also the substituted anilines which were obtained, although not 
 connected with the foundation of the coal-tar colour industry, 
 have been of great value in its after development. These few 
 references to observations on the early work carried on at the 
 Royal College of Chemistry, for the sake of science only, show, 
 in fact, what valuable material was produced for the coming new 
 industry ; indeed, without the research of Mansfield, it could 
 never have become an industry. 
 
i 4 4 THE BRITISH COAL-TAR INDUSTRY 
 
 The foregoing brings the work of the Royal College of 
 Chemistry up to near the date when I became a student there ; 
 and it will, perhaps, be well if I here refer to my young days, 
 and state how it came to pass that 1 had the good fortune to 
 study under Hofmann, especially as it will enable me to say a 
 few words in reference to one of his old pupils, Mr Thomas 
 Hall, B.A., who has done much for the cause of science. 
 
 As long ago as I can remember, the question of what pursuit I 
 should follow was constantly before me. Even when very young, 
 I interested myself in several subjects of a mechanical kind, and 
 worked at them to the best of my ability ; and elementary as the 
 experience then gained was, it had a lasting influence upon me. 
 When I was between twelve and thirteen years of age, a young 
 friend was good enough to show me some chemical experiments ; 
 amongst these were some on crystallisation, which seemed to me 
 most marvellous phenomena : as a result, my choice was fixed, 
 and it became my desire to be a chemist, if possible, as I saw that 
 there was in this science something far beyond the mechanical 
 and other pursuits I had been previously occupied with. At 
 this time I left the school I was attending, and entered the City 
 of London School, of which Dr Mortimer was then head master. 
 Here lectures were given on chemistry and natural philosophy ; 
 indeed, I believe this was the first school in which experimental 
 science was taught. The lecturer was one of the masters, Mr 
 Thomas Hall, an old student of Hofmann's who had obtained 
 all the chemical knowledge he possessed by working at the Royal 
 College of Chemistry. To attend these lectures was a source 
 of great pleasure to me. There was also a yearly examination in 
 science, and the examiner was also one of Hofmann's pupils, 
 and his first assistant, none other than my friend Mr, now Sir, 
 Frederick Abel. In the City of London School 1 was con- 
 sequently brought directly under Hofmannic influence, if I may 
 so term it, for all who came in contact with those who worked 
 with him had infused into them by induction his enthusiasm for 
 chemistry. Mr Hall very soon took an interest in me, and 
 installed me as one of his lecture assistants. Science, however, 
 was not allowed to interfere with the ordinary school curriculum, 
 so that the lectures, and the preparations for them, were delegated 
 to the interval for dinner, and being very much interested in pre- 
 paring the experiments, I not unfrequently found this interval 
 had passed before I left off work ; but, fortunately, I never 
 
HOFMANN MEMORIAL LECTURE 145 
 
 found that the abstinence thus caused acted prejudicially upon 
 me. Whilst with Mr Hall, I heard much of the Royal College 
 of Chemistry and its Professor, and after my master had very 
 kindly had several interviews with my father who wished me to 
 be an architect and not a chemist it was my good fortune to 
 be allowed to follow my bent, and go to the Royal College of 
 Chemistry, in Oxford Street. 
 
 Before passing from my schooldays, I feel I must say a few 
 more words about my old schoolmaster, to whose kindness I 
 owe so much. Thomas Hall was a born teacher, who took an 
 individual interest in his scholars, studying their characters, and 
 stimulating any special qualities he saw they possessed, and, at 
 the same time, inculcating the highest moral qualities. He hated 
 anything that was mean or underhand, and, at the same time, was 
 very genial and kind-hearted ; this may be gathered from the 
 fact that the boys used to speak of him as Tommy Hall. His 
 influence on behalf of science, especially the science of chemistry, 
 was great ; it appears, from a list of old City of London School 
 boys, kindly given me by Mr John Spiller, that more than thirty 
 boys in whom he had taken an interest afterwards worked at the 
 Royal College of Chemistry, and of these I may mention the 
 following as having contributed papers to our Transactions : 
 
 J. J. Bowrey, J. T. Brown, Frank Clowes, W. H. Deering, 
 Edward Divers, J. A. Newlands, F. J. M. Page, W. H. Perkin, 
 Alexander Pedler, J. Spiller, and W. Thorp. 
 
 I entered the Royal College of Chemistry when I was in my 
 fifteenth year, at the time when that institution became part of 
 the School of Mines, but I only took up the study of chemistry. 
 After seeing Dr Hofmann with my father, the first person I 
 encountered in the laboratory was the Assistant, Mr W. Crookes, 
 who set me to study the reactions of the metals. 
 
 There was no theatre at the Royal College then, and the 
 students had to go to the Museum of Practical Geology in 
 Jermyn Street to hear the lectures on chemistry, which involved 
 a rather serious loss of time ; but the lectures made up for this, 
 as Hofmann spared no pains in making them as interesting, in- 
 structive, and perfect as he possibly could, illustrating, as far as 
 practicable, everything by experiment, so that the facts were 
 firmly impressed upon the mind. At that time he also had a 
 very efficient lecture assistant, the late Mr Witt. Hofmann was 
 good enough to let me attend these lectures a second time. 
 
 TO 
 
146 THE BRITISH COAL-TAR INDUSTRY 
 
 When going through the ordinary course of qualitative and 
 quantitative analysis, the students working at research appeared 
 to me to be superior beings, something beyond ordinary persons ; 
 and being possessed with a desire to join their ranks, the ordinary 
 course, and also gas analysis by Bunsen's method, was quickly 
 gone through. Hofmann then set me to work at research, and 
 very curiously gave me as a subject the hydrocarbon anthracene, 
 or, as it was generally called in those days, paranaphthalene. To 
 obtain this, pitch was taken as the starting-point, but as it was 
 found that this method of preparation was a very tedious one to 
 carry out in the laboratory, Hofmann kindly obtained some of 
 the crude product for me from Mr Cliff, of Bethels Tar Works. 
 As is well known, Hofmann especially at that period was 
 much interested in the formation of organic bases from hydro- 
 carbons, and the object of my investigation was to produce, if 
 possible, a nitro compound, and then convert this into a base by 
 reduction. However, anthracene refused to give a nitro com- 
 pound, and consequently no base could be obtained, but, in the 
 course of my work, I prepared the compound we now know as 
 anthraquinone, and also the chlorine and bromine derivatives of 
 anthracene. But these substances could not be got to yield in- 
 telligible results on analysis, and at that time it never occurred 
 either to Hofmann or myself that there was any likelihood of 
 Dumas and Laurent's formula for the hydrocarbon (i.e. C^H^) 
 being incorrect. The consequence was that this research was 
 set aside, but I shall show further on that the experience I then 
 gained was of great importance to me several years later, when I 
 commenced to work at the production of alizarin. 
 
 Hofmann next set me to work to study the action of chloride 
 of cyanogen on naphthylamine in the same way that he had 
 examined the action of this gas on aniline. In those days there 
 were no depots where pure products for research could be obtained 
 as there now are, and for this inquiry even the naphthalene had 
 to be purified in the laboratory ; this research was soon completed, 
 but was not written out and published until nearly twelve months 
 afterwards. It was brought before the Chemical Society when the 
 meetings were held in Mr Pepper's house in Cavendish Square. 
 
 Hofmann had a marvellous power of stimulating his students, 
 and of imparting to them his own enthusiasm ; he took the 
 strongest personal interest in their work, visiting three or four 
 times in the week even those who were going through the 
 
HOFMANN MEMORIAL LECTURE 147 
 
 reactions, while those engaged in research work were seen daily 
 by him, and if anything of special interest was going on, more 
 than once in the day. His power of directing research was also 
 most remarkable ; with the aid of a few watch-glasses, a glass 
 rod, and a small gas flame he would make a number of experi- 
 ments, and from the information thus gained tell his students 
 how to proceed with their work. I well remember how one day, 
 when the work was going on very satisfactorily with most of us 
 and several new products had been obtained, he came up and com- 
 menced examining a product of the nitration of phenol which one 
 of the students had obtained by steam distillation ; taking a little 
 of the substance in a watch-glass, he treated it with caustic alkali, 
 and at once obtained a beautiful scarlet salt of what we now know 
 to be orthonitrophenol. Several of us were standing by at the 
 time, and, looking up at us in his characteristic and enthusiastic 
 way, he at once exclaimed, " Gentlemen, new bodies are floating 
 in the air." I mention this just as an example of the way in 
 which he used to stimulate us by his own example. 
 
 After I had completed the research on the action of chloride 
 of cyanogen on naphthylamine, Hofmann promoted me to the 
 position of an assistant in his research laboratory ; I was then 
 seventeen years of age. Mr A. H. Church, now Professor 
 Church, was among the assistants in the laboratory. This position 
 proved most valuable to me. 
 
 At this time Professor Cahours came over from Paris to work 
 with Hofmann on the allyl compounds, a research in which Pro- 
 fessor Church and I had to assist. They then commenced their 
 splendid work on the phosphorus bases, and I well remember the 
 excitement and interest which prevailed when Paul Thenard's 
 triethylphosphine was first produced by the action of zinc ethyl 
 on phosphorus trichloride, and Hofmann's delight when he found 
 it was vigorously acted on by methyl and also ethyl iodide, pro- 
 ducing white, crystalline, phosphonium iodides. 1 was occupied 
 with this research until I left the Royal College. 
 
 I may here refer to an incident which shows how greatly 
 Hofmann was interested in his scientific work. One day, when 
 he was going his usual rounds in the general laboratory, a student 
 standing not far from him poured a quantity of concentrated 
 sulphuric acid into a thick glass bottle he was holding in his hand, 
 which contained a small quantity of water ; the consequence was 
 that the heat evolved caused it to crack and the bottom to fall 
 
148 THE BRITISH COAL-TAR INDUSTRY 
 
 out. Some of the acid splashed up from the floor into HofmanrTs 
 eye, and we feared would have a permanently injurious effect 
 upon it. Hofmann was sent home in a cab, and had to be kept 
 in bed in a dark room during several weeks, his old friend, Dr 
 Bence Jones, attending him. But during this time, and notwith- 
 standing his sufferings, he was so anxious about his work that we 
 used to have to visit him in his darkened bedroom, to report 
 progress and also to receive any instructions he had to give. 
 
 Whilst in the research laboratory I had the privilege of meet- 
 ing St Claire Deville, who came to London for the purpose of 
 exhibiting specimens of sodium and aluminium at a lecture given 
 by the Rev. T. Barlow at the Royal Institution, of which the 
 lecturer was Secretary. 
 
 Whilst assistant under Hofmann, I had but little time for 
 private work in the daytime ; as, however, I wished to continue 
 research work, part of a room at home was fitted up as a rough 
 laboratory, and there I was able to work in the evenings or during 
 vacations. In this laboratory a research was carried on conjointly 
 with Mr Church on some colouring matters derived from di- 
 nitrobenzene and dinitronaphthalene. One of the products we 
 then obtained afterwards proved to be amidoazonaphthalene, or, 
 as we called it, azodinaphthyldiamine. This appears to have been 
 the first case of a definite compound being obtained of the azo 
 class and shown to possess dyeing powers. As Dr Caro has 
 referred to this in his notice in the Berichte of the late Peter 
 Griess, I need not make any further observations on the subject 
 here (Ber., 1892, 25, 4, ion). 
 
 At this period much interest was taken in the artificial forma- 
 tion of natural organic substances ; but at the time I was at the 
 Royal College of Chemistry, although the theory of compound 
 radicles, the doctrine of substitution, etc., were occupying much 
 attention, very little was known of the internal structure of com- 
 pounds and the conception as to the method by which one com- 
 pound might be formed from another was necessarily very crude. 
 
 Thus, in the Report of the Royal College of Chemistry, 
 published in 1849, Hofmann refers to the artificial formation of 
 quinine as a great desideratum, and then states : 
 
 "It is a remarkable fact that naphthalene, the beautiful hydro- 
 carbon of which immense quantities are annually produced in the 
 manufacture of coal gas, when subjected to a series of chemical 
 processes, may be converted into a crystalline alkaloid. This 
 
HOFMANN MEMORIAL LECTURE 149 
 
 substance, which has received the name of naphthalidine, contains 
 20 equivalents of carbon, 9 equivalents of hydrogen, and i 
 equivalent of nitrogen." (C = 6. O = 8.) 
 
 " Now if we take 20 equivalents of carbon, 1 1 equivalents of 
 hydrogen, i equivalent of nitrogen, and 2 equivalents of oxygen, 
 as the composition of quinine, it will be obvious that naphtha- 
 lidine, differing only by the elements of 2 equivalents of water, 
 might pass into the former alkaloid simply by an assumption of 
 water. We cannot, of course, expect to induce the water to 
 enter merely by placing it in contact, but a happy experiment 
 may attain this end by the discovery of an appropriate meta- 
 morphic process." 
 
 In fact there was but little other ground to work upon in 
 many instances than this kind of speculation. 
 
 As a young chemist I was ambitious enough to wish to work 
 on this subject of the artificial formation of natural organic com- 
 pounds. Probably from reading the above remarks on the 
 importance of forming quinine, I began to think how it might 
 be accomplished, and was led by the then popular additive and 
 subtractive method to the idea that it might be formed from 
 toluidine by first adding to its composition CJfri^ by substituting 
 allyl for hydrogen, thus forming allyltoluidine, and then removing 
 2 hydrogen atoms and adding 2 atoms of oxygen, thus 
 
 2(C 10 H 18 N) + 3 = C 20 H 24 N 2 2 + H 2 
 
 Allyltoluidine. Quinine. 
 
 The allyltoluidine having been prepared by the action of 
 allyl iodide on toluidine, was converted into a salt and treated 
 with potassium dichromate ; no quinine was formed, but only a 
 dirty reddish-brown precipitate. Unpromising though this result 
 was, I was interested in the action, and thought it desirable to 
 treat a more simple base in the same manner. Aniline was 
 selected, and its sulphate was treated with potassium dichromate ; 
 in this instance a black precipitate was obtained, and, on exami- 
 nation, this precipitate was found to contain the colouring matter 
 since so well known as aniline purple or mauve, and by a number 
 of other names. All these experiments were made during the 
 Easter vacation of 1856 in my rough laboratory at home. Very 
 soon after the discovery of this colouring matter, I found that it 
 had the properties of a dye, and that it resisted the action of light 
 remarkably well. 
 
150 THE BRITISH COAL-TAR INDUSTRY 
 
 After the vacation, experiments were continued in the even- 
 ings when I had returned from the Royal College of Chemistry, 
 and combustions were made of the colouring matter. I showed 
 it to my friend Church, with whom I had been working, on his 
 visiting my laboratory, and who, from his artistic tastes, had a 
 great interest in colouring matters, and he thought it might be 
 valuable and encouraged me to continue to work upon it ; but 
 its evident costliness and the difficulties of preparing aniline on 
 the large scale, made the probability of its proving of practical 
 value appear very doubtful. Through a friend, I then got an 
 introduction to Messrs Pullar, of Perth, and sent them some 
 specimens of dyed silk. On I2th June 1856, I received the 
 following reply : 
 
 c< If your discovery does not make the goods too expensive, 
 it is decidedly one of the most valuable that has come out for a 
 very long time. This colour is one which has been very much 
 wanted in all classes of goods, and could not be obtained fast on 
 silks, and only at great expense on cotton yarns. I enclose you 
 pattern of the best lilac we have on cotton it is dyed only by one 
 house in the United Kingdom, but even this is not quite fast, 
 and does not stand the tests that yours does, and fades by 
 exposure to air. On silk the colour has always been fugitive : 
 it is done with cudbear or archil, and then blued to shade." 
 
 This somewhat lengthy extract is quoted because it gives a 
 glimpse at the state of the dyeing trade in reference to this shade 
 of colour at that period. 
 
 This first report was very satisfactory ; the " if " with which 
 it commenced was, however, a doubtful point. 
 
 During the summer vacation, however, the preparation of the 
 colouring matter on a very small, technical scale was undertaken, 
 my brother (the late T. D. Perkin) assisting me in the operations, 
 and, after preparing a few ounces of product, the results were 
 thought sufficiently promising to make it desirable to patent the 
 process for the preparation of this colouring matter. This was 
 done on 26th August 1856 (Patent No. 1984). A visit was then 
 made to Messrs Pullar's, and experiments on cotton dyeing were 
 made, but, as no suitable mordants were known for this colouring 
 matter, only the pale shades of colour, produced by the natural 
 affinity of the dye for the vegetable fibre, were obtained ; these, 
 however, were admired. Experiments on calico printing were 
 also made at some print works, but fears were entertained that it 
 
HOFMANN MEMORIAL LECTURE 151 
 
 would be too dear, and, although it proved to be one of the most 
 serviceable colours as regards fastness, yet the printers were not 
 satisfied with it because it would not resist the action of chloride 
 of lime like madder purple. 
 
 Although the results were not so encouraging as could be 
 wished, I was persuaded of the importance of the colouring 
 matter, and the result was that, in October, I sought an interview 
 with my old master, Hofmann, and told him of the discovery 
 of this dye, showing him patterns dyed with it, at the same time 
 saying that as I was going to undertake its manufacture, I was 
 sorry that I should have to leave the Royal College of Chemistry. 
 At this he appeared much annoyed, and spoke in a very dis- 
 couraging manner, making me feel that perhaps I might be taking 
 a false step which might ruin my future prospects. I have some- 
 times thought that, appreciating the difficulties of producing such 
 compounds as aniline and this colouring matter on the large scale, 
 Hofmann perhaps anticipated that the undertaking would be a 
 failure, and was sorry to think that I should be so foolish as to 
 leave my scientific work for such an object, especially as I was 
 then but a lad of eighteen years of age ; and I must confess that 
 one of my great fears on entering into technical work was that it 
 might prevent my continuing research work, but I determined 
 that, as far as possible, this should not be the case. 
 
 Still, having faith in the results I had obtained, I left the 
 College of Chemistry and continued my experiments, and found 
 that not only aniline, but also toluidine, xylidine, and cumidine 
 gave a purple colouring matter when oxidised. 
 
 The following is a copy of the principal part of the complete 
 specification of the patent I took out at this time : 
 
 DYEING FABRICS 
 
 " The nature of my invention consists in producing a new 
 colouring matter for dyeing with a lilac or purple colour stuffs 
 of silk, cotton, wool, and other materials in the manner 
 following : 
 
 " I take a cold solution of sulphate of aniline, or a cold 
 solution of sulphate of toluidine, or a cold solution of sulphate 
 of xylidine, or a cold solution of sulphate of cumidine, or a 
 mixture of any one of such solutions with any others or other of 
 them, and as much of a cold solution of a soluble bichromate as 
 
152 THE BRITISH COAL-TAR INDUSTRY 
 
 contains base enough to convert the sulphuric acid in any of the 
 above-mentioned solutions into a neutral sulphate. I then mix 
 the solutions and allow them to stand for 10 or 12 hours, 
 when the mixture will consist of a black powder and a solution 
 of a neutral sulphate. I then throw this mixture upon a fine 
 filter, and wash it with water till free from the neutral sulphate. 
 I then dry the substance thus obtained at a temperature of 100 
 C., or 212 F., and digest it repeatedly with coal-tar naphtha, 
 until it is free from a brown substance which is extracted by the 
 naphtha. Any other substance than coal-tar naphtha may be 
 used in which the brown substance is soluble and the colouring 
 matter is not soluble. I then free the residue from the naphtha 
 by evaporation, and digest it with methylated spirit, or any other 
 liquid in which the colouring matter is soluble, which dissolves 
 out the new colouring matter. I then separate the methylated 
 spirit from the colouring matter by distillation, at a temperature 
 of iooC. or 2 1 2 F." 
 
 Fresh quantities of colouring matter were prepared and taken 
 to Scotland, and, although the method of applying it by means 
 of lacterin (casein) was then found to give very good results, 
 yet the printers who tried it did not show any great enthusiasm ; 
 and even Messrs Pullar began to fluctuate in their opinion as to 
 the advisability of erecting plant for its manufacture, and wrote : 
 " Should it appear that it will not be of service to printers, 
 it will be questionable whether it would be wise to erect works 
 for the quantity dyers alone will require." In January 1867, 
 Mr R. Pullar, however, advised me to see Mr Thos. Keith, a 
 silk dyer of Bethnal Green, London, and, after making a few ex- 
 periments with the colouring matter, and exposing the specimens 
 he dyed to the light for some time, he was much pleased with the 
 result, and encouraged me to go on with its production. 
 
 I was then joined in the undertaking by my father who 
 was a builder, and had sufficient faith in the project to risk the 
 necessary capital and also by my brother, who also had a good 
 knowledge of building, and, as he had taken part in the pre- 
 liminary experiments on the preparation of the dye, his assistance 
 proved most valuable, especially as he was possessed of good 
 business capabilities. Plans were prepared and a site obtained at 
 Greenford Green, near Harrow, and in June 1857 the building 
 of the works was commenced. 
 
HOFMANN MEMORIAL LECTURE 153 
 
 At this time, neither I nor my friends had seen the inside of 
 a chemical works, and whatever knowledge I had was obtained 
 from books. This, however, was not so serious a drawback as 
 at first it might appear to be, as the kind of apparatus required 
 and the character of the operations to be performed were so 
 entirely different from any in use that there was but little to 
 copy from. 
 
 In commencing this manufacture, it was absolutely necessary 
 to proceed tentatively, as most of the operations required new 
 kinds of apparatus to be devised and tried before more could be 
 ordered to carry out the work on any scale. 
 
 But the mechanical were not the only difficulties. Benzene 
 at this time was only made to a very limited extent, as there was 
 but little use for it, and it was only after making several inquiries 
 that it was ascertained where it could be obtained. That used at 
 first came from Messrs Miller & Co., of Glasgow. It was also 
 of very unequal quality, and required refractionating before use ; 
 its price was 55. per gallon. No nitric acid sufficiently strong for 
 the preparation of nitrobenzene could be obtained commercially, 
 and, as we did not want to complicate our works by manu- 
 facturing the substance, experiments were made with a mixture 
 of sodium nitrate and sulphuric acid, using the latter in rather 
 larger proportions than necessary to give an acid sodium sulphate. 
 This method was found to succeed on the small scale, but, when 
 working with large quantities, special apparatus had to be devised, 
 and a great many precautions had to be taken to regulate the 
 operation ; however, very large quantities of nitrobenzene were 
 made by it. Nitrobenzene had never been prepared in iron 
 vessels before this time. 
 
 It was only three years before the works were started that 
 Bchamp had made the interesting discovery that finely divided 
 iron and acetic acid were capable of converting nitrobenzene into 
 aniline ; had it not been for this discovery, the coal-tar colour 
 industry could not have been started. To carry this process out 
 on the large scale, special apparatus was also required, and, on 
 account of the energy of the action which takes place, special 
 precautions had to be adopted ; but no great difficulties were 
 encountered in this operation. Potassium bichromate at that 
 date fluctuated between 9fd. and nd. per lb., and was therefore 
 a costly product. 
 
 Many more details might be gone into in reference to the 
 
154 THE BRITISH COAL-TAR INDUSTRY 
 
 difficulties to be contended against at the starting of the industry, 
 but sufficient has been said to give some idea of them ; however, 
 in less than six months after the building of the works was com- 
 menced, namely, in December 1857, aniline purple, or Tyrian 
 purple, as it at first was called, was in use for silk dyeing in Mr 
 Keith's dye-house. 
 
 But in dyeing large quantities of silk, difficulties were again 
 encountered, on account of the great affinity of the colouring 
 matter for the fibre causing unevenness, and some time was taken 
 up in experimenting on this subject, until eventually it was found 
 that by dyeing in a soap bath a very pure and even colour could 
 be produced. This process was afterwards found to be the most 
 suitable for dyeing silk with magenta, Hofmann's violet, and 
 many other colouring matters. 
 
 Aniline purple having now been proved to be an important 
 colouring matter, which could be produced on a manufacturing 
 scale, it attracted much attention, and, as a consequence, many 
 others commenced its manufacture, and began to experiment with 
 aniline, especially in France ; all kinds of oxidising agents were 
 used, but potassium dichromate still proved to be the best, the 
 next best being chloride of copper, the use of which was patented 
 by Dale and Caro, in 1860. 
 
 The French manufacturers were not long before they succeeded 
 in producing the colouring matter (the French patent being 
 invalid, owing to a mistake as to the date it was necessary to 
 take it out in reference to that of the English patent), and in 
 using it in dyeing their goods, both silk and cotton. The 
 calico printers of this country then began to be alive to the 
 necessity of following them, and this made the demand for the 
 aniline purple which the French now began to call mauve so 
 great that, notwithstanding the continued increase which had been 
 taking place in the works at Greenford Green, it could not be 
 kept pace with. At this time, a very beautiful archil colour had 
 been produced by Messrs Guinon, Marnas, & Bonnet, called 
 French purple ; this also was applied to calico printing, and the 
 printers in this country who could not get a supply of aniline 
 purple used this until their requirements could be met. A little 
 before this, Mr Pullar and I separately discovered a process for 
 mordanting cotton, so that it could be dyed with aniline purple to 
 any depth of colour, and thus it became of much more value to 
 the cotton dyer than it was so long as its natural affinity for the 
 
HOFMANN MEMORIAL LECTURE 155 
 
 fibre could alone be relied upon. The process consisted in the 
 use of tannin and a metallic oxide. 
 
 For calico printing, the colouring matter was first applied in 
 combination with lacterin, albumin, or gluten, but endeavours 
 were soon made to find some new method by which these might 
 be dispensed with, and I worked for some considerable time 
 on this subject at the Dalmonach Print Works, Alexandria, 
 Dumbartonshire, where the colour was first practically used for 
 printing in this country. I devised a process, which consisted in 
 printing on a lead salt, converting this into a salt containing a 
 fatty acid by means of soap, and then dyeing in a soap bath con- 
 taining the colouring matter ; the fatty lead salt then took up the 
 colouring matter, whilst the soap prevented the white from being 
 stained ; this process was patented by myself and Mr Mathew 
 Grey. It produced beautiful shades of colour, but could not be 
 used where combinations with other colours were required, and 
 therefore did not prove useful. 
 
 Printers then experimented on the use of tannin and a 
 metallic oxide, the process used in cotton dyeing devised by 
 Mr Pullar and myself ; a modified form of this process has 
 become the most important used. Another process was also 
 very largely used, patented by M. Schultz and myself, which 
 consisted in forming an insoluble arsenite of alumina and colour- 
 ing matter on the fibre, the colours produced in this way being 
 very brilliant, as well as fast to washing. Before the aniline 
 purple could be introduced for dyeing woollen and mixed fabrics, 
 some weeks were also spent at Bradford in finding out suitable 
 methods of applying it. 
 
 Thus it will be seen that, in the case of this new colouring 
 matter, not only had the difficulties incident to its manufacture 
 to be grappled with, and the prejudices of the consumer over- 
 come, but, owing to the fact that it belonged to a new class of 
 dyestuffs, a large amount of time had to be devoted to the study 
 of its applications to dyeing, calico printing, etc. It was, in fact, 
 all pioneering work clearing the road, as it were, for the intro- 
 duction of all the colouring matters which followed, all the pro- 
 cesses worked out for dyeing silk, cotton, and wool, and also for 
 calico printing, afterwards proving suitable for magenta, Hofmann 
 violet, etc. 
 
 All this time a host of experimentalists continued making 
 trials with aniline and all kinds of chemicals, and early in 1859, 
 
156 THE BRITISH COAL-TAR INDUSTRY 
 
 three years after the discovery of aniline purple, or mauve, 
 M. Verguin discovered fuchsine, also called magenta and roseine, 
 and, later on, rosaniline by Hofmann. 
 
 From what has been said above, it will be seen that the dis- 
 covery of this colouring matter was made under more favourable 
 auspices than that of mauve : everything was ready for its pro- 
 duction and application, it was also an easier product to manu- 
 facture and relatively to the aniline used was formed in much 
 larger quantities than mauve was, but it was not nearly so fast 
 against light, and when first experimented with I thought this 
 would have been very detrimental to its extensive use, remember- 
 ing the experience that I had gone through with mauve ; but 
 things had changed, and the love of brilliancy had begun to 
 outrun the regard for durability, indeed, as is well known, 
 magenta has proved to be one of the most successful of the 
 coal-tar colours ever discovered. M. Verguin's process was a 
 very remarkable one, and it has never transpired whether he 
 was led to it by any scientific reasoning or not ; it will be 
 remembered that it consists in heating commercial aniline and 
 anhydrous tetrachloride of tin nearly up to the boiling-point of 
 the mixture ; it was first carried out by Messrs Reynard Bros., 
 of Lyons. 
 
 We were thus indebted to France for the second step in the 
 coal-tar colour industry. Soon other processes were invented for 
 the production of magenta, but the most practical one, after 
 M. Verguin's, was that in which mercury nitrate was used ; large 
 quantities of colouring matter were made by this method. 
 
 The fuchsine, or magenta, first made in France, was but very 
 imperfectly purified, and a good deal of that afterwards made in 
 Germany simply consisted of the " melt " produced by heating 
 aniline with mercury nitrate. 
 
 Being naturally interested in this new colouring matter, I 
 made many experiments with it, and in a lecture I delivered before 
 this Society, on i6th May 1861 (Jour. Chem. Soc. y 1862, 14, 
 230) (when I was honoured by the presence of Michael Faraday), 
 an account of some of the results obtained by its examination 
 was given, in which it was shown that it was the salt of an 
 organic base (a fact at that time believed in by some, but doubted 
 by others) precipitated by alkalis and at the same time dissolved 
 by them to some extent, yielding colourless solutions, and that 
 its nitrate could be obtained in the form of octahedra, having 
 
HOFMANN MEMORIAL LECTURE 157 
 
 a beautiful green metallic reflection ; this was the first occasion, 
 I believe, on which it was described as a crystalline compound. 
 Attention was also called to the fact that its salts could not con- 
 tain oxygen, which was afterwards confirmed by Hofmann ; and 
 it was further pointed out that other products were formed along 
 with it, one possessing an orange colour (chrysaniline), and another 
 a purple colour (violaniline, mauvaniline, etc.). 
 
 In speaking of the manufacture of rosaniline in this country, 
 I must first refer to another of Hofmann's pupils, Edward 
 Chambers Nicholson, of the firm of Simpson, Maule & Nichol- 
 son, who brought the manufacture of this compound to a state 
 of perfection which, I believe, has not been surpassed so far as 
 purity is concerned up to the present time. 
 
 It is of interest to trace the manner in which Messrs Simpson, 
 Maule & Nicholson became connected with the coal-tar colour 
 industry. They were originally manufacturers of fine chemicals, 
 etc. When aniline purple was found to be successful, and was 
 exciting a great deal of interest, this and other firms were anxious 
 to manufacture it, and consequently wished to have a licence for 
 the purpose, but no agreement could be come to. They were 
 then very desirous of manufacturing nitrobenzene for our use in 
 producing aniline. At first they could not do this at a sufficiently 
 low price, but eventually succeeded in producing it cheaply enough 
 to make it worth our while to supplement our own make by 
 theirs, as the demand for aniline purple was then so rapidly 
 increasing. In this way they soon became considerable producers 
 of nitrobenzene ; they then set to work to prepare aniline, which 
 after a time they succeeded in doing. In this manner they 
 leisurely, as it were, became fully prepared to go a step further, 
 and become manufacturers of colouring matters. 
 
 Dr David Price at this time joined the firm, and Nicholson 
 and he apparently experimented with the products he had patented 
 in 1859, namely violin, purpurin, and roseine, obtained by oxidis- 
 ing aniline with lead peroxide ; these colouring matters, however, 
 were not found to be of practical value. They then turned their 
 attention to the newly discovered colouring matter, fuchsine. 
 This they commenced manufacturing, giving it the name of one 
 of Dr Price's products, roseine. 
 
 H. Medlock, another of Hofmann's pupils at the Royal 
 College of Chemistry, took out a patent on i8th January 1860, 
 for the production of magenta, by heating aniline with arsenic 
 
158 THE BRITISH COAL-TAR INDUSTRY 
 
 acid ; eight days later, Nicholson filed a similar patent, but did 
 not proceed with it when he learnt what Medlock had done. 
 Medlock's patent is notorious for the amount of litigation that 
 arose owing to the occurrence in it of the word " anhydrous." 
 The formation of magenta by the use of arsenic acid proved in 
 the hands of Nicholson, and also of others, a great improvement 
 on the previous processes, and for a long time was the process 
 for the production of this colouring matter, until, in fact, it was 
 superseded by the use of nitrobenzene instead of arsenic acid. 
 
 One of the things Hofmann used to impress on those of his 
 students who were engaged at research work was the great 
 importance of preparing their products in as nearly pure a 
 condition as possible especially those which were to be submitted 
 to analysis ; some of us used to think that we should get as 
 good results by examining the substances when crystallised 
 fewer times than he required, especially when the products were 
 difficult to obtain and the quantities became smaller and smaller 
 on each recrystallisation ; but he was right. Nicholson, when at 
 the Royal College, made several investigations under Hofmann's 
 direction, studying the compounds of phosphoric acid with 
 aniline ; the formation of cumidine from cumene from cuminic 
 acid ; also caffeine and some of its compounds ; and, in con- 
 junction with F. A. Abel, he investigated strychnine. He also 
 appears to have been an adept at combustions, as he made the 
 combustion of benzene for Mansfield ; his name appearing also 
 in de la Rue's paper on cochineal as having made one of the 
 combustions of nitrococcusic acid. There is no doubt that 
 Hofmann's teaching as to the importance of working with pure 
 materials was strongly impressed upon Nicholson when carrying 
 on these researches, and that it greatly influenced him when he 
 became engaged in the manufacture of colouring matters. It is 
 only right to add that Dr D. Price, with whom he was for some 
 time associated in this industry, and whom I knew when at the 
 Royal College of Chemistry as a most thorough, painstaking, 
 and careful worker, would also second his efforts in this respect. 
 I may also add that I feel sure Hofmann's influence in this 
 direction had also a considerable influence on my own after- 
 career as a chemist. 
 
 At first Messrs Simpson, Maule & Nicholson supplied 
 magenta, or roseine, as they called it, to the dyers in alcoholic 
 solution, but afterwards, when they had obtained it in a pure 
 
HOFMANN MEMORIAL LECTURE 159 
 
 condition, they sold it in crystals (usually the oxalate). In their 
 process of purification they boiled the crude solution of the 
 colouring matter with milk of lime, and collected the base which 
 deposited from the clear solution thus obtained, and from this 
 prepared the desired salts. 
 
 By this time the coal-tar colour industry had become one of 
 no mean dimensions in this country, and also in France, and 
 it was quickly developing in Germany and elsewhere. The 
 number of colours was also increasing, for not only had mauve 
 or aniline purple and fuchsine been discovered, but Girard and 
 De Laire had made their remarkable discovery of imperial violet 
 and blue de Lyon by heating aniline with fuchsine, thereby as 
 is now known phenylating this colouring matter. 
 
 When first speaking of fuchsine, I mentioned that it was 
 discovered by M. Verguin, and, from a practical point of view, 
 this may be considered correct. Nevertheless it appears to have 
 been first seen as far back as 1856, when Natanson (Annalen der 
 Chemie und Pharmacie, 1856,98, 297) observed that in heating 
 aniline and chloride of ethylene in a sealed tube to 200 C., the 
 mixture becomes of a rich blood-red colour ; Hofmann also, 
 in 1858, when acting on aniline with carbon tetrachloride, ob- 
 tained, besides carbotriphenyltriamine, a small quantity of this 
 substance as a secondary product, which he describes as " a very 
 soluble substance of a magnificent crimson colour." * 
 
 In the Report of the Exhibition of 1862 (Class II., sec. A, 
 p. 126), Hofmann, in speaking of the discovery of this colouring 
 matter, says : " It may be said to have been discovered at two 
 different times according as the question is considered from a 
 scientific or industrial point of view ; " and at p. 126: 
 " Industrially, the discovery of aniline red was made by Messrs 
 Verguin and Renard Brothers of Lyons/* 
 
 The investigation Hofmann made with the Nicholson pro- 
 ducts soon set at rest the conflicting views which at first existed 
 in reference to this colouring matter, and proved that it was a 
 
 1 About two years after M. Verguin's discovery of fuchsine, the use of 
 carbon tetrachloride and aniline as a means of preparing this colouring 
 matter was tried, for reasons connected with patent rights, by MM. Monnet 
 and Drury of Lyons. They first employed a temperature of ii6-ii8 C. 
 until the reaction between these two substances was over, and then heated 
 the product up to 170 or 180 C. By this means of working, they apparently 
 obtained a larger yield than Hofmann, but the process never became a 
 practical one. See Moniteur Scientifique, t. Hi., i5th January 1861. 
 
160 THE BRITISH COAL-TAR INDUSTRY 
 
 well-defined triamine which he renamed rosaniline forming 
 salts free from oxygen. He then regarded the base, which had 
 the formula C 2 oH 2 iN 3 O, as a hydrate of the anhydrous compound 
 C 2 oH 19 N 3 . Hofmann examined many of the salts of rosaniline 
 those with one molecule of acid, the ordinary salts used in 
 dyeing, and the hydrochloride with 3 mols. of acid. He also 
 obtained the interesting compound, leucaniline, by treating 
 rosaniline with reducing agents, a compound which has its 
 representation in all triphenylmethane colouring matters. The 
 investigation is a memorable one, as being the first investigation 
 which gave correct information respecting the formula of a 
 coal-tar colouring matter. 
 
 It had been observed by manufacturers that some varieties of 
 aniline yield much more rosaniline than others, samples boiling 
 at temperatures much higher than the boiling-point of the pure 
 compound being found particularly adapted for the production of 
 the red ; and it appears that Nicholson had ascertained that pure 
 aniline was incapable of yielding rosaniline. Hofmann studied 
 this subject, using aniline prepared from indigo and from pure 
 benzene, and his experiments confirmed Nicholson's. The idea 
 then naturally suggested itself, that the toluidine contained in 
 commercial aniline might be the source of the colouring matter. 
 But, on making experiments with toluidine (orthotoluidine was 
 not then known) it was found that this base also was incapable 
 of producing the dyestuff; on taking a mixture of aniline and 
 toluidine, however, it was at once produced in quantity, showing 
 that both bases were necessary for its production (Report, 
 International Exhibition, 1862, Class II., sec. A, p. 130). 
 
 This discovery was of great importance and interest, and 
 explained most of the facts connected with the use of anilines of 
 different boiling-points. In the case of mauveine, this discovery 
 was not of so great importance as in the case of rosaniline, because 
 pure aniline yields a purple colouring matter (pseudomauveine), 
 as well as mixtures of aniline and toluidine. 
 
 Mauve had also been obtained in a pure crystallised condition, 
 but technically this was not found of much advantage, as the 
 colours obtained with it in this condition were only slightly 
 superior to those obtained with the less expensive precipitated 
 colouring matter which was usually supplied to the consumer. 
 
 Having examined aniline red or rosaniline, Hofmann was also 
 desirous of investigating aniline purple or mauve, but when he 
 
HOFMANN MEMORIAL LECTURE 161 
 
 spoke to me on the subject, the colouring matter was already 
 under investigation in my own laboratory. 
 
 The crystallised aniline purple sent into the market was the 
 acetate of the base to which I gave the name mauveine. This 
 base is remarkable for its stability and tinctorial power. Its 
 investigation (Proc. Roy. Soc., 1864, 12, 713) showed that it 
 possesses the formula C 2 7H 24 N 4 , and that, unlike rosaniline, it is 
 not a hydroxy compound. Moreover, the base is a strongly 
 coloured compound of a blue-violet colour. When treated with 
 reducing agents, it yields a leuco compound, but this is so 
 sensitive to the action of oxygen that on exposure to the air it 
 instantly changes back to mauveine. Its ordinary salts are pro- 
 duced from i mol. of base and i mol. of acid. From a more 
 recent research on this colouring matter (Jour. Chem. Soc., 1879, 
 717), I have shown that a dihydrochloride and corresponding 
 platinum salt can be obtained, and the characteristic changes 
 which a solution of this substance in concentrated sulphuric acid 
 undergoes on dilution, namely, from a dull green to a blue, and 
 lastly to a purple, show that probably salts formed by the union 
 of mauveine with more than 2 mols. of acid exist. The ordinary 
 commercial product has also been shown to consist of two 
 colouring matters, one forming very soluble and apparently un- 
 crystallisable salts called pseudomauveine, having the formula 
 C 2 4H 2 oN 4 , and produced from pure aniline ; the other forming 
 less soluble and beautifully crystalline salts of the formula 
 C 2 7H 2 4N 4 , derived from paratoluidine and aniline. This colour- 
 ing matter, unlike rosaniline, does not freely undergo changes 
 with reagents on account of its great stability, so that few 
 derivatives have been obtained from it serving to elucidate its 
 constitution, which is still unknown. 
 
 Messrs Simpson, Maule & Nicholson, after engaging in the 
 manufacture of rosaniline for some time, undertook that of Girard 
 and De Laire's imperial violet and bleu de Lyon, obtained by 
 heating a salt of rosaniline with aniline (Pat., January 1861). 
 
 Mr Nicholson spent much time in studying the conditions 
 most favourable to the production of these compounds, especially 
 the blue, so as to obtain it in a pure condition, and in this he 
 was very successful. This was due to his knowledge of the 
 importance of using pure materials in its manufacture. The 
 rosaniline base he used was not merely the best he produced for 
 the preparation of rosaniline salts, but he purified it much further 
 
 ii 
 
1 62 THE BRITISH COAL-TAR INDUSTRY 
 
 by means of methylated spirit ; the aniline was prepared for the 
 purpose from the purest benzene he could obtain ; he also paid 
 much attention to the selection of the best acid to use in com- 
 bination with rosaniline, and found that weak organic acids, such 
 as acetic and benzoic acids, were the most suitable. In this way 
 he eventually obtained the blue in a condition of purification 
 unequalled by others. 
 
 Provided with the purified blue by Nicholson, Hofmann soon 
 discovered that the base had the formula C 38 H33N 3 O ; this he 
 regarded as a hydrate of the compound C 38 H 31 N 3 , of which he 
 obtained a hydrochloride of the composition C 38 H 31 N 3 HC1. The 
 blue was converted by reducing agents into a leuco compound. 
 
 As far back as 1850 (Phil. Trans., 1, 93, Jour. Chem. Soc., 3, 
 283), when engaged in his researches on the molecular constitution 
 of the volatile organic bases, Hofmann had endeavoured to displace 
 the hydrogen in aniline by phenyl, by heating it with phenol, 
 but was unsuccessful ; we can, therefore, easily understand his 
 delight when he found that on boiling rosaniline with aniline the 
 colouring matter became phenylated. The long-desired method 
 of effecting the displacement of hydrogen by phenyl had, in fact, 
 been discovered, and we find that no sooner had he recognised that 
 the blue was a triphenylrosaniline than he telegraphed the result 
 to Paris. 1 The Comptes rendus of the sitting of the Academy 
 of 1 8th May 1863 contains the following note : 
 
 " M. Le Secretaire Perpetuel communique une Courte Note 
 de M. Hofmann conue dans les termes suivants. 
 
 " Bleu d'Aniline. En poursuivant mes recherches sur les 
 couleurs d'aniline, je suis arrive a un resultat tres simple ; le 
 bleu d'aniline est la rosaniline triphenylique : une molecule de 
 rosaniline et trois molecules d'aniline renferment les elements 
 d'une molecule de bleu d'aniline et trois molecules d'ammoniaque." 
 The paper, communicating fuller details of his results on this 
 colouring matter, was read on 6th July of the same year (Compt. 
 rend.) 1863, 57, 25). Speaking in this paper of Nicholson, he 
 pays him this tribute : " That in him was united the genius of 
 the manufacturer and the habits of a scientific investigator." 
 
 1 Hofmann had made the discovery apparently on the same day, for 
 Professor M c Leod, who was his assistant at that time, gives me an entry 
 from his diary dated i8th May 1863, which runs thus: "The doctor told me 
 that he had made a fine discovery, and that aniline blue is the triphenylated 
 rosaniline. Rosaniline, C 20 H 19 N 3 H 2 O ; aniline blue, C 20 H 16 (C 6 H 5 ) 5 N 3 H 2 O." 
 
HOFMANN MEMORIAL LECTURE 163 
 
 We find the discovery of the phenylation of rosaniline after- 
 wards bearing fresh fruit in the hands of De Laire, Girard, and 
 Chapoteaut, who established the remarkable fact that when boiled 
 with its own hydrochloride, aniline acted in a similar manner, 
 producing diphenylamine and ammonia ; by using aniline 
 hydrochloride and toluidine, they, in like manner, obtained 
 phenyltoluylamine (Compt. rend.) 1866, 63, 91). 
 
 Aniline blue having proved to be triphenylrosaniline, it was 
 soon seen that the different shades of violet imperial were 
 rosanilines more or less phenylated. 
 
 Nicholson also found that, on heating acetate of rosaniline to 
 200 215 C., ammonia was disengaged, and a purple colouring 
 matter produced, which he called regina purple. This substance 
 was found to be a monophenylrosaniline (patented 2oth January 
 1862). 
 
 One of the great obstacles in the way of the application of 
 aniline blue was its slight solubility in water, which rendered the 
 dyeing operations unsatisfactory ; this also militated against its 
 use in calico printing for some time (the most suitable process 
 for its use for this purpose first found being that of Schultz and 
 myself with arsenate of alumina, but with this long steaming and 
 afterwards clearing in a soap bath was required ; the colours thus 
 obtained, however, were very pure and very durable). Nicholson 
 naturally was very desirous of overcoming this obstacle, and no 
 doubt the well-known process of rendering indigo soluble by 
 dissolving it in sulphuric acid, and thus converting it into a 
 sulphonic acid, occurred to him ; at any rate, by experimenting 
 in this direction, he succeeded in obtaining the desired result and 
 patented the process (ist June 1862). Nicholson obtained two 
 sulphonic acids a mono and a tri the first being known as 
 Nicholson's blue, and the latter as soluble blue, and it is owing 
 to the discovery of these derivatives of aniline blue or triphenyl- 
 rosaniline that this colouring matter became of such importance. 
 
 This method of treating aniline blue was very interesting as 
 being the first instance of sulphonating an aniline colour, a 
 process which of late years has become of so much importance, 
 not only in rendering difficultly soluble dyes soluble, but 
 also in changing the chemical nature of the colouring matters, 
 and thus extending their applications as dyes, as in the case of 
 rosaniline sulphonic acid. 
 
 It was Nicholson who succeeded in isolating the yellow qr 
 
164 THE BRITISH COAL-TAR INDUSTRY 
 
 orange colouring matter which is formed in the manufacture 
 of rosaniline ; he prepared it in a pure state, and called it 
 phosphine. Hofmann undertook the examination of this dye, 
 and showed that it is represented by the formula C 2 oH 17 N 3 , 
 differing from that of rosaniline in containing 2 atoms of 
 hydrogen less ; the base is capable of forming salts with i or 2 
 molecules of hydrochloric acid, the nitrate being remarkable for 
 its insolubility. 
 
 After discovering that aniline blue or bleu de Lyon was a 
 triphenylrosaniline, Hofmann was very naturally inclined to 
 experiment on rosaniline with the agents he had used so success- 
 fully in his experiments on the molecular constitution of the 
 volatile organic bases, namely, the haloid compounds of the 
 alcohol radicles, to see what influence these radicles would have 
 if introduced into the base : he found that they had, like phenyl, 
 though not to the same extent, a blueing effect, the colour 
 changing from red to purple, and then to violet as the hydrogen 
 atoms were gradually displaced, colouring matters being produced 
 which were found to be of great beauty when applied to silk, etc. 
 In his first paper on these products (Compt. rend.) 1863, 57, 30), 
 he gives an account of the action of methyl, ethyl, and amyl 
 iodides on rosaniline, and amongst the products he obtained at 
 that time describes the highest ethylated derivative he had 
 succeeded in producing as the iodethylate of triethylrosamline, 
 C2oHi 6 (C 2 H 5 ) 3 N3 . C 2 H 5 I. 
 
 He patented the method of producing these colouring matters 
 on 22nd May 1863. 
 
 It is easy to see how Hofmann was led to the production of 
 these compounds in the regular sequence of his work, but it is 
 curious that E. Kopp had evidently prepared some of them as 
 long back as 1861. E. Kopp remarks in his paper in the 
 Comptes rendus, 1861, 52, 363, " I have only stated in my notice 
 these substitutions as a hypothesis, but their existence is very 
 real ; I have already obtained some of them, and it is a 
 remarkable thing that the red shade disappears, and is converted 
 into a violet, becoming bluer and bluer as the hydrogen is dis- 
 placed by the hydrocarbons." It appears that he sent some 
 specimens of his products to M. Dumas. 
 
 When Hofmann patented the use of methyl, ethyl, and amyl 
 iodides for the preparation of these colouring matters, it seemed 
 almost incredible that substances such as these, which had 
 
HOFMANN MEMORIAL LECTURE 165 
 
 hitherto only been used in research, should be employed in the 
 manufacture of a dye ; but such circumstances have constantly 
 arisen in the history of this remarkable industry aniline itself, 
 the parent of artificial colours, being an example and nothing 
 now appears to be too rare or difficult to prepare, to be used in 
 its development. 
 
 It is difficult to understand why E. Kopp did not go on with 
 his work on these substitution compounds, unless it was owing 
 to the fact that rosaniline was expensive in his days, and he 
 considered the alcoholic haloids too costly to employ for practical 
 purposes. 
 
 The Hofmann violets were the most brilliant in colour of any 
 which had been produced, and proved not to be so costly as 
 might be anticipated, as the iodine from the ethyl iodide used 
 could be mostly recovered ; but these colouring matters have 
 not the stability of mauve or imperial violet, and at first it was 
 thought that their use would be limited, but the increasing 
 desire for brilliancy was still superseding that for stability, and 
 the result was, that these colouring matters were very largely 
 used, and interfered very considerably with the sale of the 
 mauve and imperial violets, except for pale shades of colour, 
 when, unless the colouring matter used be stable, the goods fade 
 so quickly as to be of little value. 
 
 The products formed on heating mauveine salts with aniline 
 apparently are not comparable with those obtained from ros- 
 aniline, and although the product becomes bluer no ammonia is 
 evolved ; from my later experiments, it seems most likely that 
 the aniline used takes no part in the change, the blueing being 
 a change in the colouring matter, the consequence of the 
 temperature employed. 
 
 When treated with ethyl iodide, mauveine behaves unlike 
 rosaniline, yielding a beautiful colouring matter, which is of a 
 redder shade, and not bluer as in the latter case. This colouring 
 matter, called dahlia (patented on 6th November 1863), consists 
 of a monethylic derivative of mauveine, its hydrochloride being 
 represented by the formula C 2 7H23(C 2 H5)N 4 HC1. No further 
 change is effected by ethyl iodide, and it is uncertain whether 
 the product is a substitution or an addition compound (it may 
 be remarked here that at times some quantity of a dark, blue- 
 black, almost insoluble substance containing iodine is also 
 produced). 
 
1 66 THE BRITISH COAL-TAR INDUSTRY 
 
 This dahlia or ethylmauveine was used by the calico printers 
 and dyers to some extent, though not largely, on account of its 
 costliness. It is, however, a colouring matter which gives 
 shades of very considerable stability on exposure to light. 
 
 The discovery that the introduction of such radicles as phenyl 
 or ethyl altered the colour of rosaniline so greatly, made it of 
 interest to see whether other kinds of hydrocarbon groups could 
 be introduced to modify its tint. Amongst other products, 
 brominated turpentine was used, and on heating it with rosaniline 
 hydrochloride dissolved in methylated spirit or methyl alcohol 
 under pressure, it was found that a very beautiful purple or 
 violet colouring matter could be produced ; the process was 
 patented in 1864, and large quantities of a colouring matter, 
 known as Britannia violet, were prepared in this manner. At 
 first it was thought that the hydrocarbon radicle of the brominated 
 turpentine entered the rosaniline, but it now appears most 
 probable that the product consisted of methylrosanilines produced 
 by the action of methyl bromide formed from hydrogen bromide 
 resulting from the decomposition of the bromo compound. 
 The colouring matter was more soluble than Hofmann's ethyl 
 violet, but I could not succeed in crystallising it, and, therefore, 
 it was not subjected to analysis. 
 
 When the base of Britannia violet is acted on by acetyl 
 chloride, two products are obtained, namely, a violet colouring 
 matter much bluer in shade than the original violet, and a bluish- 
 green compound. The base of this latter has a very feeble 
 affinity for acids, and does not combine with acetic acid, whilst 
 the base of the violet compound does so freely, and in virtue of 
 these different properties the two colouring matters are easily 
 separated. The green dye proved to be of practical value, and 
 considerable quantities of it were prepared for the calico printers. 
 It was known as Perkin's green, but after a time it was displaced 
 by iodine green. It has not hitherto been investigated. For 
 its manufacture, large quantities of terchloride of phosphorus 
 were prepared, from which and acetic acid large quantities of 
 acetyl chloride were made another instance of the use of a 
 research reagent on the large scale. 
 
 The last investigation relating to colouring matters carried out 
 by Hofmann in this country was that of the very interesting sub- 
 stance known as quinoline blue, discovered by Greville Williams, 
 of which the latter gave an account in the Chemical News for 
 
HOFMANN MEMORIAL LECTURE 167 
 
 nth October 1860 (p. 219). A beautiful specimen of the 
 crystallised substance was displayed in the exhibition of 1862 
 under the name of cyanin. Quinoline blue was a very pure 
 shade of colour, and, although an expensive product, attempts 
 were made to introduce it as a dye ; unfortunately, although pro- 
 duced from bases of remarkable stability, it was very fugitive, 
 goods dyed with it fading very quickly indeed when exposed to 
 the light its sensitiveness being so great that on placing it under 
 a glass positive photograph and exposing to sunlight, after only 
 a short time a quinoline blue positive picture was produced. 
 
 Hofmann separated from quinoline two blue compounds, to 
 one of which he gave the formula CaoH^g^I, and to the other 
 the formula C28H 3 5N 2 I. According to later researches, the blue 
 is a condensation product derived from quinoline amyliodide and 
 lepidine amyliodide. 
 
 C 29 H 35 N 2 I + H 2 O + HI 
 
 Quinoline amyl Lepidine amyl Cyanine or diamyl 
 
 iodide. iodide. cyanine iodide. 
 
 This formula differs from that given by Hofmann to one of 
 the products he examined by an atom of carbon only. 
 
 After I left the Royal College of Chemistry, the researches 
 on the phosphorus bases in which I had been helping were con- 
 tinued by Drs Leibius and Holzmann, to whose able assistance 
 Hofmann refers in one of his papers ; but in carrying out the 
 part of this work relating to the phosphammonium, phosph- 
 arsonium, and arsammonium compounds, another assistant was 
 active, who is referred to by Hofmann in the following words : 
 
 " I conclude this memoir with the expression of my best 
 thanks for the untiring patience with which Mr Peter Griess 
 has assisted me in the performance of my experiments on the 
 phosphorus bases. The truly philosophical spirit in which this 
 talented chemist has accompanied me through the varying 
 fortunes of this inquiry, will always be one of my pleasing 
 recollections." 
 
 We know how the high opinion thus expressed by Hofmann 
 of Griess not only lasted, but became enhanced as time went on ; 
 and although Griess was not one of Hofmann's pupils, I cannot 
 refrain from thus referring to him here, as several of his most 
 important early researches on the diazo compounds were made 
 within the walls of the Royal College of Chemistry, thereby con- 
 necting this Institution with work which of late years has had 
 
1 68 THE BRITISH COAL-TAR INDUSTRY 
 
 such a marvellous influence on the development of the coal-tar 
 colour industry. But it is not my intention, nor indeed is it 
 necessary for me, to go into the history of the diazo compounds, 
 as this has been so very ably done by my friend Caro in his 
 memoir of Peter Griess, whom he held in such high esteem, and 
 who was also one of his greatest friends. 
 
 Hofmann's departure was not only a cause of regret to those 
 who had worked under him and to all his friends ; it was a 
 heavy loss also to the country at large, as no one had ever done 
 so much for the cause of chemical science in the kingdom as 
 Hofmann did, nor had anyone exercised to such an extent that 
 wonderful power he possessed of stimulating the enthusiasm of 
 his students and of inciting in them a love of chemistry and of 
 scientific research. His success is especially striking when the 
 early history of the Royal College of Chemistry is taken into 
 account especially its financial difficulties, the dissatisfaction of 
 some of the subscribers, and the want of understanding as to the 
 value of scientific research shown both by them and the public at 
 large. When all these circumstances are considered, we cannot 
 but marvel at the courage and indomitable determination he dis- 
 played, which enabled him to overcome all difficulties and to per- 
 severe in maintaining the high standard of teaching he adopted 
 at the beginning, as well as to continue the prosecution of scientific 
 research for its own sake. 
 
 Notwithstanding the immense amount of work Hofmann 
 must have had to attend to in connection with the building 
 and fitting up of the new chemical laboratories of the Frederick 
 William University of Berlin, which took place during the first 
 four years after he left England, namely, from May 1865 to 
 May 1869, no break occurred in his scientific activity, each year 
 producing accounts of fresh work accomplished. It was not, 
 however, until 1869 that he published anything fresh in con- 
 nection with the coal-tar colours, but in this year several com- 
 munications appeared. 
 
 Having found that the production of rosaniline depended 
 on the presence of two bases, aniline and toluidine, he naturally 
 carried his investigation of the subject further, and experimented 
 with xylidine (meta). However, on heating this base with oxidis- 
 ing agents, either alone or in presence of toluidine, no colouring 
 matter was obtained ; but when it was heated with pure aniline, 
 a red was formed, which he called xylidine red, which was supposed 
 
HOFMANN MEMORIAL LECTURE 169 
 
 to be a homologue of rosaniline, probably of the composition 
 C 2 2H 2 5N 3 O. The colour produced on wool and silk by this 
 dyestuff was almost as bright as that of rosaniline itself (Ber.^ 2, 
 377). In a second paper relating to this subject, published in 
 conjunction with Martius (Ber. y 2, 411), an account is given of 
 similar experiments with an isomer of xylidine, amidoethylbenzene, 
 which, from the more recent researches of Beilstein and Kilhlberg 
 (Zeitsch. f. Chem. [2], 5, 524), we now know must have been a 
 mixture of the ortho and para compounds. No red colouring 
 matter was formed from this on boiling it with an oxidising 
 agent, either alone or mixed with toluidine or even with aniline, 
 thus affording proof of the interesting fact that an ethyl group 
 cannot take the place of a methyl group in the interaction which 
 is involved in the production of colouring matters of the rosani- 
 line class. 
 
 After the discovery of mauve and magenta, many experi- 
 ments were made with a-naphthylamine, as a source of colouring 
 matter, and a variety of products was obtained and patented ; 
 but it is unnecessary for me to enter into an account of these 
 here, as most of them were found to be of no technical value. 
 I may, however, allude to two naphthalene derivatives which 
 have proved useful ; the first of these, naphthazarin, was dis- 
 covered by Roussin in 1861, who thought it was artificial alizarin. 
 This beautiful substance, which is now known to be a dihydroxy- 
 /3-naphthoquinone, lay dormant for a long time, but, owing to 
 the discovery of improved methods of producing it, has of late 
 come into use for dyeing black on wool. The second was dis- 
 covered by Martius, and is known as " Martius yellow " or 
 dinitro-a-naphthol. These were the principal colouring matters 
 derived from naphthalene known prior to 1867, when Schiendl 
 discovered the naphthalene red now known by the name of 
 Magdala red, a substance remarkable for the beautiful fluor- 
 escence of its solution. The original process for its preparation 
 consisted in heating naphthylamine, acetic acid, and potassium 
 nitrite together, and then adding more naphthylamine and again 
 heating until the desired colouring matter was produced. 
 
 Hofmann investigated this red, and assigned to it the formula 
 C 30 H 21 N 3 (Ber., 1869, 2, 374). 
 
 As this colouring matter and the above formula appeared 
 to be related to an old friend of mine, azodinaphthyldiamine 
 (amidoazonaphthalene), I made it the subject of experiments, 
 
i yo THE BRITISH COAL-TAR INDUSTRY 
 
 and found that it was easily produced on heating amidoazo- 
 naphthalene with an acid and naphthylamine, an action taking 
 place which it was thought involved the displacement of an atom 
 of hydrogen by naphthyl and the formation of ammonia : 
 
 C 20 H 15 N 3 + C 10 H 9 N = C 30 H 21 N 3 + NH 3 . 
 
 Amidoazo- Magdala red. 
 
 naphthalene. 
 
 The colouring matter was called azotrinaphthyldiamine (Proc. 
 Roy. Int., I4th May 1869). 
 
 In a second paper, published in July of the same year, on the 
 nature of naphthalene red, Hofmann confirms my observations 
 (Ber., 2, 413). 
 
 It has since been shown, however, by Julius (Ber., 1886, 
 19, 1365), that the action which occurs when amidoazo- 
 naphthalene is treated with naphthylamine is not nearly so 
 simple as above indicated, and that the formula of the hydro- 
 chloride of Magdala red is C 30 H2iN 4 Cl, not C 30 H 2 2N 3 C1. 
 
 The research on Magdala red led Hofmann to study the 
 compound produced by the action of aniline on amidoazobenzene, 
 a substance described by Martius and Griess, but discovered by 
 Dale and Caro in 1863, and called by them induline. The ex- 
 amination of this product was afterwards continued by Hofmann 
 in conjunction with Geyger, under the heading of colouring 
 matters obtained from aromatic azodiamines, and published in 
 1872 (Ber., 5, 472). They called this substance azodiphenyl 
 blue, and showed that its hydrochloride had the formula 
 C 18 H 16 N 3 C1. 
 
 In 1869 Hofmann also continued his researches on chrys- 
 aniline, studying the action of methyl and ethyl iodide on the 
 base ; he obtained trimethyl and triethyl substitution products 
 (Ber., 2, 378). 
 
 In preparing Hofmann violet, it was found that on precipi- 
 tating the colouring matter from its aqueous solution by means 
 of sodium chloride, a certain quantity of a bluish-green product 
 remained in solution which could not be separated (though im- 
 proved in colour) by the addition of sodium carbonate ; this was 
 precipitated by means of picric acid, and as it proved to be a 
 valuable green dye, it, after a time, was supplied in small 
 quantities to dyers under the name of iodine green. It was then 
 found by J. Keisser (French patent, i8th April 1866) that the 
 colouring matter could be obtained in much larger quantities by 
 
HOFMANN MEMORIAL LECTURE 171 
 
 methylating rosaniline, dissolved in methyl alcohol, with methyl 
 iodide, the operation being completed at a comparatively low 
 temperature, and eventually it was obtained in a pure crystallised 
 state. This substance being evidently related to the methyl- 
 rosanilines, Hofmann was naturally interested in it, and with 
 Girard undertook its investigation (Ber., 2, 440). 
 
 The results they obtained, on analysing the iodo compound, 
 led them to represent it by the formula 
 
 Cao^ie I >j 
 (CH 8 ) 8 / JN 
 
 f CH 8 I. 
 CH.I.H0. 
 
 They found that this compound decomposes when heated at 
 the temperature of boiling water for a few hours, and instantly at 
 130 150 C., becoming changed into a violet colouring matter ; 
 in fact, it behaves like an ammonium or addition product. As 
 the complicated history of the methyl and ethyl derivatives 
 developed, it was found that the formula above given required 
 to be modified to some extent ; but this is in no way surprising, 
 as it is practically impossible by analysis alone to arrive at a true 
 conclusion as to the constitution of a compound of such high 
 molecular weight, so unstable and so difficult to obtain pure. 
 
 Another green dyestuff to which Hofmann directed his 
 attention at this time was aldehyde green, produced by the action 
 of aldehyde on rosaniline in presence of sulphuric acid, whereby 
 a blue colouring matter is formed, which is transformed into 
 the green by the action of an aqueous solution of sodium thio- 
 sulphate. Lauth, apparently, was the first to produce the blue 
 compound, in 1861, by subjecting a solution of rosaniline in 
 alcohol, methyl alcohol, acetic acid, or acetone to the action of 
 zinc chloride and other metallic salts, but the conversion of the blue 
 into the green was accomplished by Cherpin in 1862. This was 
 the first aniline green dye discovered (emeraldine, which was of 
 no value, excepted), and was much used. Hofmann showed that 
 aldehyde green contained sulphur, and assigned to it the com- 
 position indicated by the formula C22H27N 3 S 2 O, representing 
 its formation by the following equation, 
 
 C 20 H 19 N 3 + C 2 H 4 O + 2H 2 S = C 22 H 27 N 8 S 2 O 
 
 (Bcr., 1870,3,761). 
 
 The next researches it will be most convenient to refer to, 
 though not quite the next as to date, are those on the methyl 
 
172 THE BRITISH COAL-TAR INDUSTRY 
 
 violets ; but, before considering these it may be mentioned that, 
 in continuation of his researches on rosaniline derivatives, 
 Hofmann, in 1873 (Ber., 6, 263), examined the violet obtained 
 by Hobrecker by the action of benzyl chloride and methyl iodide 
 on a solution of rosaniline in methyl alcohol, assigning to it the 
 formula C 2 oH 16 (C 7 H 7 ) 3 N 3 CH 3 I. 
 
 Until long after the commencement of the coal-tar colour 
 industry, chemists and experimenters directed their attention 
 chiefly to aniline as a source of colouring matter ; but in 1861 
 Lauth made some experiments on the product Hofmann obtained 
 by acting with methyl iodide on aniline, which he described as 
 methylaniline (Jour. Chem. Soc., 1851, 3, 296), but which recent 
 researches have shown is a mixture of methylaniline and di- 
 methylaniline, and by oxidising this he obtained violet colouring 
 matters. Writing of these in 1867, Lauth says (Laboratory, 
 1867, 138), "The violets obtained from methylaniline possess 
 a richness and purity which leave nothing to be desired. . . . 
 Nevertheless, they were not adopted by manufacturers, who, 
 indeed, at the time mentioned (1861) attached less importance 
 to the beauty of a colour than to its permanence. In this latter 
 respect the methylaniline violets do not excel, and, consequently, 
 dyers would have nothing to do with them. Gradually, how- 
 ever, people have become accustomed to colours which fade on 
 exposure to the solar rays. . . . Accordingly, two years after the 
 experiment made by myself, Dr Hofmann succeeded in introduc- 
 ing these results." 
 
 These remarks confirm those already made in reference to the 
 gradual change in public opinion which led to the disregard of 
 permanency in favour of brilliancy of colour. 
 
 Lauth further remarks that Hofmann's method of producing 
 these colouring matters is the inverse of that proposed by him ; the 
 aniline being first converted into rosaniline and then methylated, 
 whilst in his case this operation is first performed on the aniline. 
 
 It would, however, not have been practicable to carry out 
 this process if the aniline had to be methylated with methyl 
 iodide, because the base thus prepared would be too expensive 
 to use as the raw material for the preparation of colouring 
 matters. On account of the success of the Hofmann violet, 
 experiments were made in France with the object of preparing 
 methylaniline by a different and more economical process, so as 
 to commercially produce Lauth's violet, and this was at that time 
 
HOFMANN MEMORIAL LECTURE 173 
 
 considered especially desirable by some manufacturers, because 
 the production of rosaniline in France was the monopoly of one 
 house, and, therefore, derivatives of this colouring matter could 
 not be economically made by others. 
 
 Eventually a successful process was discovered by M. Bardy, 
 chemist to the firm of Poirrier & Chapat, which consists in 
 heating a mixture of aniline hydrochloride and methyl alcohol 
 in a closed vessel to a high temperature. As is now well known, 
 though not at first recognised, this process yields a mixture of 
 mono- and di-methylaniline, consisting chiefly of the latter. 
 Large quantities of methylated aniline were soon produced by 
 this process, and used in the preparation of a violet colouring 
 matter which was manufactured by Messrs Poirrier & Chapat, 
 and called by them violet de Paris ; a large block of this, 
 weighing about 150 kilos, was exhibited in the Paris Exhibi- 
 tion of 1867. The question then arose as to whether violet de 
 Paris was identical or isomeric with methylrosaniline violet. 
 Lauth considered that it was isomeric, and remarks : u Hofmann 
 violets consist of methylated and ethylated rosaniline, and 
 rosaniline is derived from a molecule of aniline and two molecules 
 of toluidine. The violet de Paris, on the contrary, is produced 
 from pure aniline free from toluidine, transformed into methyl- 
 aniline, which is isomeric with toluidine. This methylaniline 
 when oxidised is converted into the violet, which may have a 
 composition analogous to that of methylated rosaniline, but must 
 differ from the latter in the same manner as methylaniline differs 
 from toluidine." 
 
 Hofmann, being naturally interested in the relationship of 
 these colouring matters, investigated the subject, and published 
 his results in 1873 (for., 6, 352). He first studied the 
 conditions under which the colouring matter could be formed, 
 showing that violet could be produced from pure dimethylaniline 
 obtained by the distillation of trimethylammonium hydrate ; he 
 also came to the conclusion from the examination of the colouring 
 matter that it was a methylchlorhydrate of trimethylrosaniline : 
 
 C 20 H 16 (CH 8 ) 3 N 3 .CH 3 .C1, 
 the base being 
 
 C 20 H 16 (CH 3 ) 3 N 3 .CH 3 .OH. 
 
 He prepared iodine green by methylating this compound ; 
 also its leuco compound. 
 
174 THE BRITISH COAL-TAR INDUSTRY 
 
 This research must have been a very difficult and laborious 
 piece of work, and although Hofmann's views as to the constitu- 
 tion of the dimethylaniline violet are not those now accepted, 
 the accuracy of his work has not been impugned. 
 
 The long controversy which arose, soon after the time when 
 Hofmann published his constitutional formula of rosaniline, as 
 to the constitution of this colouring matter, belongs to another 
 chapter, and need not be referred to here. 
 
 Mention has already been made of the process for methylating 
 aniline discovered by Bardy, which consisted in heating this base 
 with hydrochloric acid and methyl alcohol. In 1871 Hofmann 
 and Martius (Ber., 4, 742) made some experiments in reference 
 to this method, working at higher temperatures than those usually 
 employed (28o-3OO C.), and continuing the heating for a con- 
 siderable time ; in this way they obtained, besides methyl, and 
 dimethylaniline, a quantity of basic oil of higher boiling-point, 
 which eventually proved to be a complex mixture of methylated 
 homologues of dimethylaniline, the products of an intramolecular 
 change or atomic wandering. 
 
 These remarkable researches, like so many other purely 
 scientific discoveries, ere many years had passed, were found to 
 be of technical value in connection with the coal-tar colour in- 
 dustry, the cumidine that is so extensively used in the preparation 
 of some of the diazo colours being made by the method of Hof- 
 mann and Martius by heating xylidine with hydrochloric acid and 
 methyl alcohol to a high temperature, about 300 C. 
 
 Reverting once more to the early days of the coal-tar colour 
 industry, I may now mention that the liquors from which mauve 
 was precipitated were found to contain a red colouring matter 
 which I succeeded in separating, although the amount obtainable 
 was very small. This proved to be a beautiful dye producing 
 crimson-red shades on silk. It was afterwards discovered that 
 it could be produced by the oxidation of mauveine, and it was 
 prepared in considerable quantity in this way, but was a very 
 expensive product, and therefore not very largely used. This 
 dyestuff was known first as "aniline pink," and afterwards as 
 " safranine." In 1865 a colouring matter having the properties 
 of safranine was produced without the use of mauveine by F. 
 Duprey, by heating commercial aniline dissolved in acetic acid 
 with lead nitrate. It was then obtained by acting on commercial 
 aniline with nitrous acid and oxidising the mixture with arsenic 
 
HOFMANN MEMORIAL LECTURE 175 
 
 acid. The colouring matter prepared in this way was examined 
 by Hofmann and Geyger (Ber., 1872, 5, 531). They found 
 it to be a base forming crystalline salts, among others a hydro- 
 chloride having the composition C^i^iN^CL As they found 
 that it could not be produced from either aniline or paratoluidine, 
 or a mixture of the two, but from orthotoluidine, they regarded 
 it as a toluidine derivative. They also observed that the formula 
 above given differs from that of mauveine by C 6 H 4 , making it 
 appear possible that mauveine was phenylsafranine. In the 
 course of an investigation of the safranine, obtained by the 
 oxidation of mauveine, of which I published an account some 
 time after this (Jour. Chem. Soc., 1879, 35, 728), this substance 
 was shown to form a hydrochloride represented by the formula 
 C 20 H 18 N 4 , which differs from that of the substance examined by 
 Hofmann and Geyger by CH 2 . On examining a commercial 
 product manufactured by Messrs Guinon & Co., of Lyons, from 
 commercial aniline, both substances were found to be present, 
 showing that two " safranines " existed, and I then also showed 
 that probably a third was formed by the oxidation of pseudo- 
 mauveine. 
 
 The formula of the safranine hydrochloride obtained from 
 mauveine will be seen from the above to differ from mauveine 
 by C 7 H 6 , so that the relationship of these substances is probably 
 not of so simple a character as Hofmann and Geyger supposed, 
 though, of course, C 7 H 6 may simply mean displacement of 
 hydrogen by tolyl. No doubt a great similarity exists between 
 them, one proof of which is that their behaviour with sulphuric 
 acid is analogous. This applies both to those referred to above 
 and to the third compound since discovered. 
 
 In 1875 Hofmann made an examination of eosin (Ber., 8, 62), 
 and thus disclosed to the world an important manufacturing 
 secret, proving to demonstration the impossibility in these days 
 of long hiding from chemists the nature of any substance, how- 
 ever complex. Eosin, as is well known, was the first representa- 
 tive of a new class of colouring matters which has since become 
 of great importance. 
 
 Chrysoidine, which may fairly be termed the parent of an 
 even more important class of colouring matters, the azo dyes, 
 the introduction of which marks a new era in this branch of 
 chemistry, was investigated and publicly proclaimed by Hofmann 
 in 1877 (Ber., 10, 213). 
 
176 THE BRITISH COAL-TAR INDUSTRY 
 
 The colouring matter to which he next directed his attention 
 was pittacal, also called euppitonic acid, the interesting compound 
 discovered by Reichenbach, as far back as 1835, produced from 
 wood tar. Hofmann (Ber., 1878, 11, 1655 ; 1879, 12, 1371 and 
 2216) was led to regard this substance as hexamethoxyrosolic 
 acid, C 19 H 8 (OCH 3 ) 6 O 3 ; on treating it with ammonia, he 
 obtained a beautiful blue dyestuff, thus, 
 
 C 25 H 26 9 + 3 H 3 N = C 25 H 31 N 3 6 + 2<DH 2 , 
 which he regarded as hexamethoxypararosaniline, 
 
 C 19 H 13 (OCH 3 ) 6 N 3 0. 
 
 He then made the interesting discovery that the formation 
 of pittacal, or euppitonic acid, from dimethylpyrogallate and 
 dimethyl-methylpyrogallate took place in a manner analogous 
 to that in which pararosaniline was formed, thus, 
 
 2 . C 6 H 7 N + C 7 H 9 N = C 19 H 17 N 3 + H3 2 . 
 
 Aniline. Toluidine. Pararosaniline. 
 
 2 C 8 H 10 O 3 + C 9 H 12 O 3 = C 25 H 26 O 9 + 3H 2 , 
 
 Dimethyl- Dimethyl-methyl- Pittacol or 
 
 pyrogallate. pyrogallate. euppitonic acid. 
 
 a comparison which is of considerable interest. 
 
 Hofmann's last research in connection with the coal-tar 
 colour industry was made as late as 1887, and related to the 
 quinoline red prepared by Jacobson, in 1882, from coal-tar 
 quinoline, benzotrichloride, and zinc chloride. Hofmann, how- 
 ever, found that a better yield of colouring matter, either 
 identical or isomeric with Jacobson's, is obtained by using a 
 mixture of isoquinoline and quinaldine. Like quinoline blue 
 or cyanine, the colour is not a fast one, which as previously 
 mentioned, is remarkable, considering the stability of quinoline 
 itself. It is a somewhat remarkable coincidence that this should 
 have been the last research Hofmann made on the coal-tar 
 colours, as quinoline (or leucoline) was one of the two substances 
 he gave an account of in his first investigation published in 1843, 
 when thirty years of age. 
 
 Excepting what is said of pittacal, and the brief reference to 
 eosin and chrysoidine, the foregoing account has reference only 
 to what may be termed aniline colours, the great chapter dealing 
 with the history of technical chemistry, with which Hofmann's 
 name is indissolubly linked. 
 
HOFMANN MEMORIAL LECTURE 177 
 
 An entirely new chapter in coal-tar chemistry opens in 1868, 
 when Graebe and Liebermann (in connection with their re- 
 searches on quinones) made their great discovery of the artificial 
 formation of alizarin from anthracene. They patented their 
 process in Germany in October, and in this country on i8th 
 December of that year. Their process, it is well known, con- 
 sisted in producing dibromanthraquinone, either by brominating 
 anthraquinone in sealed tubes, or by oxidising tetrabrom- 
 anthracene, and subsequently displacing bromine by hydroxyl, 
 by fusion with alkali. 
 
 This discovery for the first time of a method of obtaining 
 a vegetable colouring matter artificially was, however, as it stood, 
 of no practical value, as such a process could not be carried out 
 on a large scale. 
 
 But why should this be mentioned here ? It may seem that 
 any reference to the alizarin industry is out of place in a notice 
 designed to elucidate Hofmann's influence on the development 
 of our knowledge of products derived from coal-tar, as he 
 apparently never took any part in the investigation of anthracene 
 derivatives. Yet it is to his influence that I can trace back my 
 interest in the subject, for, as mentioned early in this account, 
 the very first subject in research which he suggested to me was 
 to prepare a nitro compound and a base from anthracene. In 
 the course of this work I not only became thoroughly acquainted 
 with this hydrocarbon, but also prepared anthraquinone and 
 other derivatives of it, and consequently was, perhaps, more 
 fully prepared than any other chemist of the day to appreciate 
 the discovery of the relationship of alizarin to anthracene, and 
 was naturally impelled at once to attempt to adapt it to practical 
 requirements. It is more than probable that I should have paid 
 but ordinary attention to Graebe and Liebermann's work had I 
 not possessed an early attachment to anthracene, and I am glad 
 to recognise that I owe this to the knowledge and insight of my 
 great master. 
 
 Being aware of the importance of alizarin as a colouring 
 matter, and having some quantity of anthracene and anthra- 
 quinone left over from my experiments at the Royal College 
 of Chemistry, I commenced to experiment on the formation of 
 this substance, with the object of finding a process by which 
 bromine might be dispensed with. 
 
 I knew of the remarkable stability of anthraquinone : that 
 
 12 
 
178 THE BRITISH COAL-TAR INDUSTRY 
 
 it could be crystallised from concentrated sulphuric acid without 
 undergoing change, and that in making a combustion of it, if 
 the operation were at all hurried, part of the anthraquinone 
 would pass through the heated tube, and condense at the cool 
 end unaltered. 
 
 Moreover, not long before I commenced to work at the 
 artificial formation of alizarin, namely, in 1867, Wilrtz and 
 Kekule had shown that when benezenesulphonic acid was heated 
 with potassium hydrate, it gave a phenate and sulphite ; and 
 Dusart had also found that naphthalenedisulphonic acid was in 
 like manner converted into a dihydroxynaphthalene ; so that it 
 appeared probable that if a disulphonic acid of anthraquinone 
 could be obtained, it would be possible to convert it by the 
 new reaction into alizarin. 
 
 Anthraquinone was therefore heated with oil of vitriol more 
 and more strongly, until the boiling-point was nearly reached, as 
 I was determined either to obtain a sulphonic acid or destroy the 
 anthraquinone ; and at last it was found that the anthraquinone 
 had disappeared, yielding a product which was soluble in water. 
 After the excess of sulphuric acid had been removed in the usual 
 way with barium carbonate, the product was fused with caustic 
 alkali, and to my delight it changed first to violet, and then 
 became black from the intensity of its colour. On dissolving 
 the melt, a beautiful purple solution was obtained, which gave a 
 yellow precipitate when acidified, and on examination this was 
 found to dye mordanted cloth like garancine. 
 
 On the 2oth of May (1869) I sent dyed patterns to my friend 
 Mr Robert Hogg, of Glasgow, who had a very large experience 
 in reference to madder and garancine, and also of the coal-tar 
 colours from the days of the mauve dye, whose opinion I valued 
 very much in all practical matters connected with dye-stuffs, 
 especially from a commercial point of view, and he was very 
 favourably impressed with the results I had obtained. This 
 process, however, was not patented until 26th June. (About 
 the same time as I discovered this process, Graebe, Liebermann, 
 and Caro quite independently arrived at the same result in 
 Germany.) This process has proved the most permanently 
 important one yet discovered, and is the one still universally 
 used. I was also fortunate enough to discover a second process, 
 which was of great value in the early days of the industry, but is 
 not in use now so far as I know. It consisted in the use of 
 
HOFMANN MEMORIAL LECTURE 179 
 
 dichloranthracene as the starting-point, instead of anthraquinone. 
 This substance was found to readily afford a sulphonic acid, 
 which could be easily changed into anthraquinonesulphonic acid, 
 either by oxidising its solution with manganese dioxide or more 
 simply by heating it with sulphuric acid. This process was 
 patented in November 1869. 
 
 After discovering processes by which artificial alizarin could 
 be produced, the technical value of the artificially prepared dye- 
 stuff had to be ascertained. Experiments were soon made by 
 the calico printers, as no new processes had to be discovered for 
 the application of this colouring matter, those in use for madder 
 and garancine being suitable. Turkey-red dyers also experi- 
 mented with it, but some were not so successful as others, for 
 reasons easily understood afterwards, when the properties of 
 anthrapurpurin, which it contained, were better known. 
 
 The subject of price, however, was the important question, 
 because this product had to compete with those already in the 
 market, namely, madder and garancine, and therefore high prices 
 could not be obtained as in the case of a new dye. 
 
 Before this could be settled, the first thing necessary was to 
 get a supply of anthracene. This substance was not at this date 
 separated by the tar distillers, there being no use for it ; many of 
 them, in fact, knew nothing of its existence, and the question as 
 to whether it could be obtained in sufficient quantity and at a 
 sufficiently low price had to be settled. 
 
 But experiments I had made on the small scale, on the dis- 
 tillation of soft pitch, at the Royal College of Chemistry, gave 
 me confidence, and my brother and I entered into the matter 
 with great energy. 1 At first we prepared anthracene by distil- 
 ling pitch ourselves, and thought of using this as a source of this 
 hydrocarbon on an extensive scale, as we felt it was capable of 
 yielding a considerable supply. We knew, however, that it 
 could also be obtained from the last runnings of the tar stills, 
 from which it crystallised on cooling. My brother, therefore, 
 visited nearly all the tar works in the kingdom, and showed the 
 distillers how to separate the anthracene, promising to take all 
 they could make, and in this way a sufficient and rapidly increas- 
 ing supply for our requirements was soon obtained of all sorts of 
 qualities, some being not much thicker than pea soup, from the 
 
 1 My father, to whose great kindness I was so much indebted, died in 
 1864, so that our firm then consisted only of my brother and myself. 
 
i8o THE BRITISH COAL-TAR INDUSTRY 
 
 imperfect way in which it was drained. Very few tar distillers 
 in those days had hydraulic presses, such as are now used, with 
 which they could free the solid from the excess of oil. The 
 value of the anthracene was estimated by washing with carbon 
 bisulphide, afterwards alcohol was used, but for our own purposes 
 we all along used an anthraquinone test. This method was 
 afterwards worked out more perfectly on the Continent, and made 
 a practical test for both the buyer and seller ; but at the time I 
 am writing of tar distillers were not sufficiently educated in such 
 matters to use any but very simple tests. 
 
 The purification of the anthracene sufficiently for our purpose 
 had then to be worked out, and in doing this I found out a 
 curious fact, namely, that when distilled with caustic potash it 
 was much improved in quality considerably more so than when 
 distilled either alone or with caustic soda. And potash-distilled 
 anthracene was especially necessary when dichloranthracene had 
 to be prepared, as it yielded a well-crystallised, easily purified 
 product, whereas anthracene which had been distilled, either alone 
 or with caustic soda, gave a badly crystallised, sticky product, 
 which was very difficult to purify. 
 
 On examining into the action of caustic potash on anthracene, 
 it was found that if, after the anthracene had been distilled off, 
 the residue was freed from alkali by washing, and then distilled, 
 a substance very like anthracene was obtained, which Graebe 
 subsequently found to be the nitrogenous compound now known 
 as carbazol. It is by means of caustic potash that this substance 
 is now separated from crude anthracene, and the process is still 
 used to a large extent to improve the quality of anthracene. All 
 the anthracene we used at Greenford Green was treated in this 
 manner. 
 
 The purification of the anthraquinone was at first effected by 
 sublimation, followed by crystallisation. A good deal of difficulty 
 was experienced in the conversion of this substance into its 
 sulphonic acid, however, and at the high temperature at which 
 combination took place, the formation of steam from the water 
 produced at the same time led to considerable quantities of the 
 anthraquinone becoming sublimed, which, although not lost, yet 
 was a source of trouble in various ways. The means of over- 
 coming this difficulty was to use fuming sulphuric acid, with 
 which anthraquinone combined at a much lower temperature, but 
 the only acid of the kind then made was the old-fashioned Nord- 
 
HOFMANN MEMORIAL LECTURE 181 
 
 hausen acid. We imported a quantity of this, and, of course, 
 found it to work satisfactorily, but the difficulties and expense 
 connected with the carriage and transport of this substance on 
 account of its dangerous nature supplied as it then was in large 
 earthenware bottles made it unsuitable for use in this country. 
 
 The artificial alizarin we first made was produced by the 
 anthraquinone process, the method still used for its manufacture, 
 but the difficulty in preparing the sulphonic acid in those early 
 days just referred to caused us to turn our attention to the second 
 process I had discovered, in which dichloranthracene was used. 
 After finding out the best way of preparing the substance, our 
 difficulties in reference to the sulphonic acid vanished, as dichloran- 
 thracene dissolves easily in hot ordinary oil of vitriol, producing 
 dichloranthracenedisulphonic acid ; on continued heating this acid 
 oxidises, hydrogen chloride and sulphur dioxide being evolved 
 and anthraquinonedisulphonic acid formed. Without this process, 
 the manufacture of artificial alizarin in this country could not 
 have been carried on with much success in the early days of its 
 manufacture. 
 
 The conversion of the anthraquinonesulphonic acids into 
 colouring matter by treatment with caustic alkali at a high 
 temperature at first presented many difficulties when carried out 
 on the large scale. Our earliest experiments were made by heat- 
 ing the mixture in iron trays in a large air bath. Mixtures of 
 caustic potash and caustic soda were also experimented with in- 
 stead of caustic soda alone. Then the mixture was placed in a 
 revolving cylinder, heated in an air bath, small cannon balls being 
 put into the cylinder to mix the product. But all these methods 
 were only partially successful, the percentage of colouring matter 
 produced not being so high as it should have been. At last heat- 
 ing in a very strong iron boiler under pressure was resorted to, 
 and by adopting this method which is now that universally 
 used we obtained a satisfactory result. 
 
 From the experiments we made in 1869 we felt pretty con- 
 fident that artificial alizarin could be made at a price to compete 
 with madder and garancine, and before the end of the year we 
 had produced i ton of this colouring matter in the form of paste, 
 in 1870 40 tons, and in 1871 220 tons, and so on in increasing 
 quantities year by year. 
 
 The colouring matter produced from dichloranthracene was 
 chiefly anthrapurpurin containing a little flavopurpurin. Theo- 
 
1 82 THE BRITISH COAL-TAR INDUSTRY 
 
 retically it should have consisted of these products only, but 
 owing to the occurrence of a secondary action, which I need not 
 refer to here (see Lectures Soc. Arts^ 3Oth May 1879), ^ a ^ so con ~ 
 tained alizarin, which we sometimes separated when required for 
 dyeing purples. This colouring matter yielded a shade of colour 
 which answered most of the requirements of the consumers for 
 some time, as it was chiefly used by the Turkey-red dyers, and 
 the supply being limited, it was often used in combination with 
 garancine, as in this way more brilliant reds could be obtained 
 than when using garancine alone, though, of course, the use of 
 the artificial colouring matter alone yielded still clearer and more 
 fiery shades. 
 
 Dichloranthracene was afterwards found to yield a mono- 
 sulphonic acid when treated with sulphuric acid, provided the 
 temperature was kept low and the amount of acid limited ; and 
 when oxidised with manganese peroxide or other oxidising agent, 
 this yielded anthraquinonemonosulphonic acid, from which 
 alizarin alone could be obtained. But the properties of di- 
 chloranthracene-monosulphonic acid were such, and the technical 
 difficulties of carrying out the process so considerable, that it was 
 never used very successfully. Moreover, by this time, fuming 
 sulphuric acid had come into use, and anthraquinonemono- 
 sulphonic acid could be more readily produced directly from 
 anthraquinone. As we had been successful in producing artificial 
 alizarin, others did not run much risk in following our lead ; yet, 
 up to the end of 1870, the Greenford Green Works were the 
 only ones producing artificial alizarin. German manufacturers 
 then began to make it, first in small and then in increasing 
 quantities, but until the end of 1873 there was scarcely any com- 
 petition with our colouring matter in this country. 
 
 From the foregoing, it is seen that, as in the case of the 
 aniline colours, all the pioneering work connected with the 
 foundation and establishment of this branch of the coal-tar colour 
 industry was done in this country. 
 
 For the due development of this industry, it was necessary 
 not only to attend to technical processes, but also to carry on 
 scientific research in connection with it. Early in 1870, I had 
 the honour of bringing before this Society an account of some 
 experiments on the formation of the colouring matter obtained 
 from the sulphonic acids of anthraquinone, showing that it 
 contained alizarin possessed of both the chemical and optical 
 
HOFMANN MEMORIAL LECTURE 183 
 
 properties of that obtained from madder-root. At the same 
 time, attention was directed to the existence of a second colour- 
 ing matter, yielding reds more scarlet and purples of a bluer 
 shade than alizarin (Jour. Chem. Soc., 1 870, 23, 133). This second 
 colouring matter was afterwards made the subject of further 
 investigation, and shown to be an isomer of purpurin ; it was 
 therefore called anthrapurpurin (Jour. Chem. Soc., 1872, 25, 659, 
 and 1873, 26, 425). Dichlor- and dibrom- anthracene and their 
 disulphonic acids, etc., were also investigated. Anthraflavic acid, 
 discovered by Schunck in some secondary products sent to him 
 from my works, was made the subject of two researches ; in 
 the first of these, this compound was shown to be an isomer of 
 alizarin, and not to contain C 15 as supposed by its discoverer. 
 In the second, the sublimed acid was examined and found to be 
 identical with the unsublimed ; it was also shown that when 
 fused with alkali it did not yield alizarin, as stated by Schunck, 
 but a colouring matter yielding orange-red colours with alumina 
 mordants. This, Schunck and Roemer, some time afterwards 
 showed to be another isomer of purpurin which was named by 
 them flavopurpurin. 
 
 In this investigation, anthraflavic acid was found to yield a 
 diacetyl and dibenzoyl derivative, which was evidence that it con- 
 tained two hydroxyl groups like alizarin (Jour. Chem. Soc., 1873, 
 26, 19). Later on, an investigation was made on the formation 
 of anthrapurpurin, proving that, as in the case of flavopurpurin, 
 the formation of the colouring matter from the disulphonic acid 
 of anthraquinone is preceded by that of a dihydroxy derivative, 
 also an isomer of alizarin, now known as isoanthraflavic acid, 
 which, when heated with caustic alkali, is partially oxidised into 
 anthrapurpurin and partially reduced (Jour. Chem. Soc. y 1876,1. 29, 
 851). Besides these, the formation of bromalizarin (Jour. Chem. 
 Soc. y 1874, 27, 401), of /3-nitroalizarin (Jour. Chem. Soc., 1876, ii. 
 30, 578), of anthrapurpuramide (Jour. Chem. Soc., 1878, 33, 216), 
 and of the dibromanthraquinones discovered by Graebe and Lieber- 
 mann and the colouring matters obtainable from them, were 
 investigated (Jour. Chem. Soc. y 1880, 37, 554). Much work has 
 also been done in reference to this industry by Graebe and 
 Liebermann and other investigators. 
 
 The manufacture of artificial alizarin in Germany has been 
 almost entirely confined to the anthraquinone process, fuming 
 sulphuric acid being used in the preparation of the sulphonic 
 
1 84 THE BRITISH COAL-TAR INDUSTRY 
 
 acids. For this purpose very strong acid, containing about 
 40 per cent, of anhydride, was made from Nordhausen acid, 
 and used until the process of making sulphuric anhydride by 
 decomposing sulphuric acid into sulphurous oxide, oxygen, and 
 water, and recombining the two former, was introduced. 
 
 After being engaged in the coal-tar colour industry for 
 eighteen years, my connection with it, technically, came to an 
 end in 1874, when the alizarin industry had been well established 
 and was rapidly extending. 
 
 On looking back over the period, it is of interest to see the 
 wonderful progress the industry had made up to that time a 
 progress which was going on by leaps and bounds. I have no 
 statistics connected with the precise period, but four years after- 
 wards, namely in 1878 with the kind assistance of Dr Caro 
 an estimate of the value of the colours produced during that 
 year was obtained, at a time when the industry had just passed 
 its majority and was twenty-two years old. The sum amounted 
 to 3,150,000. (See Jour. Soc. Arts^ 3Oth May 1879.) Of its 
 present position, it is very difficult to speak. Certainly its pro- 
 gress has been very great since 1878 ; but chiefly owing to the 
 scientific skill bestowed upon the production of the colouring 
 matters, their cost has been greatly dimished, so that I under- 
 stand rosaniline hydrochloride, which once was worth about 
 3, 35. per ounce, may now be purchased at 2s. 9d. per lb., and 
 aniline at less than 6d. per lb. . . . 
 
 During the early days of the coal-tar colour industry, the 
 complaint was made that the prosecution of purely scientific 
 chemistry was being injured by its influence, as chemists were 
 everywhere experimenting with aniline and other products, with 
 objects of a more selfish than scientific character. It is probable 
 that there was some truth in this for a time, but it was not long 
 before a welcome change set in, and the work carried on in 
 relation to this industry was soon conducted in a scientific spirit, 
 even when the result sought for was expected to be of technical, 
 as well as where it was expected to be of scientific, value. But 
 the amount of work carried on from the latter point of view 
 increased more and more, as interesting questions connected with 
 the colouring matters and the methods by which they were pro- 
 duced presented themselves to chemists, and now if we look 
 back and consider what has been accomplished, we find that 
 this industry has directly and indirectly had a most marvellous 
 
HOFMANN MEMORIAL LECTURE 185 
 
 influence on the advancement of chemical science, especially that 
 part of it relating to the aromatic series of compounds. No 
 other industry in existence can at all be compared with it from 
 this point of view. This has arisen from a variety of circum- 
 stances, one of which is that it has not been carried on by the 
 rule-of-thumb method which has been so common in other cases. 
 Again, as it has utilised the discoveries of chemists, it has 
 handed back to them in return new products which they could 
 not have obtained without its aid, and these have served as 
 materials for still more advanced work : this kind of exchange, 
 indeed, has been going on so repeatedly, that products formerly 
 of the rarest and most complex character are now quite common 
 substances in the coal-tar colour works. 
 
 We knew that aniline was at first a rare substance, and when 
 it was afterwards proposed to use ethyl and methyl iodides in 
 the preparation of ordinary dyestuffs, it seemed incredible that 
 such substances could be introduced for such a purpose as 
 already mentioned, substances which were but rarely met with 
 even in chemical laboratories : but what are these compared with 
 the substances now in use ? their names would be too numerous 
 to mention. One of the most striking facts connected with this 
 industry is the remarkably rapid way in which it has utilised 
 new discoveries which have often been no sooner made than they 
 have been practically applied. This do doubt arises from the 
 fact that an ever-increasing army of highly trained and highly 
 gifted chemists are engaged in the industry, especially on the 
 Continent, provided with splendid laboratories, libraries of 
 scientific works, and all the most advanced appliances required 
 in scientific research ; and the members of this army are not 
 only making discoveries themselves and applying them, but are 
 always on the alert to make the discoveries of others subservient 
 to the industry. 
 
 As I have already mentioned, when this industry was first 
 instituted, organic chemistry was comparatively in its infancy, 
 especially if we regard it from our present standpoint. Kekul 
 had not then brought forward his remarkable benzene theory, 
 and after he had done so its bearings required much elucidation 
 before their importance was well understood. Only solid tolui- 
 dine was known, orthotoluidine not having been discovered, 
 although it was constantly present in the high boiling aniline 
 used in making rosaniline ; but now the facts connected with 
 
1 86 THE BRITISH COAL-TAR INDUSTRY 
 
 the ortho-, meta-, and para-position in substances containing the 
 benzene nucleus, or of the a- and ^-positions in the naphthalene 
 series, are among the most important to be considered in the 
 manufacture of colouring matters ; in fact, this industry has done 
 more to accentuate the importance and character of these positions 
 than any other kind of experimental work. 
 
 Although at the commencement of the industry a good deal 
 of work of a purely experimental character had to be done, 
 nevertheless, from the first it was carried out on scientific lines, 
 and this characteristic increased very rapidly, as is seen by the 
 early date at which mauve and magenta were obtained in the 
 pure crystallised condition : it was at this period, as previously 
 stated, that Hofmann commenced his researches on rosaniline 
 and its derivatives, and on other colouring matters, and these 
 researches, taken with those of others, bear out the observations 
 which have just been made. In looking over the work of 
 Hofmann in this field, all who have had experience in the investi- 
 gation of the subjects he undertook must realise that they pre- 
 sented no ordinary difficulties, especially as for some time he 
 had nothing to guide him in his conclusions but the analytical 
 results. In the early days of organic chemistry, it is well known 
 that on finding colouring matters in the products they were 
 examining, chemists usually regarded them as impurities, and 
 the use of animal charcoal and other means were resorted to for 
 the purpose of getting rid of them ; and those who undertook 
 to do the examination of colouring matters themselves were 
 considered as bold men, and not likely to get much result from 
 their labour. Doubtless, there was much truth in this. Hof- 
 mann, however, was a bold man, and not one to be daunted, but 
 rather inspired, by difficulties ; and from his results we see how 
 great his success was in this department of chemistry, some of 
 his work proving to be of direct practical value, whilst other 
 parts possessed important bearings both on the practical and 
 scientific development of this subject. His researches on colour- 
 ing matters extended over a quarter of a century, commencing 
 in 1862 with rosaniline, and ending in 1887 with quinoline red ; 
 and during that period there were but few years in which he did 
 not produce one or more investigations, either related to colour- 
 ing matters or the products connected with their production. 
 
 It will be obvious from what has been said, how Hofmann 's 
 early work after that of Faraday, Unverdorben, Runge, 
 
HOFMANN MEMORIAL LECTURE 187 
 
 Fritsche, Mitscherlich, and Zinin continued to pave the way 
 for the introduction of the coal-tar colour industry, also how the 
 important influence he exercised on the training of his students 
 led in the same direction. I especially refer to Mansfield, who 
 did such valuable work on coal-tar, and Nicholson, whose chemi- 
 cal education under Hofmann was such an important preparation 
 for the work he undertook in after years on rosaniline and its 
 derivatives ; and if I may speak for myself, I can only say how 
 much I owe to Hofmann's training, which fitted me to carry out 
 the work which fell to my lot in connection with the introduction 
 and development of this industry. Then if we further consider 
 the importance of the beautiful researches Hofmann made, some 
 of which yielded practical results, throwing fresh light on the 
 nature of the colouring matters and products related to them 
 which were obtained as time went on, some idea may be formed 
 of the contributions made by Hofmann and his school to the 
 coal-tar colour industry. 
 
 And yet we must bear in mind that his work in this depart- 
 ment of chemistry represents but a small part of all that he 
 accomplished indeed, the amount of scientific work he did was 
 something marvellous. 
 
X.: igoi 
 THE SYNTHESIS OF INDIGO 
 
 BY PROFESSOR R. MELDOLA, F.R.S., F.I.C. 
 
 (Journal of the Society of Arts^ 1901, p. 397) 
 
 THIS paper discusses the various synthetical processes which have been 
 used for the production of indigo. The latter portion of the paper is 
 quoted in the article on " The Indigo Crisis " : see p. 219. 
 
 188 
 
XL: 1901 
 
 THE RELATIVE PROGRESS 
 
 OF THE COAL-TAR COLOUR INDUSTRY IN 
 
 ENGLAND AND GERMANY DURING THE 
 
 PAST FIFTEEN YEARS 
 
 BY ARTHUR G. GREEN, F.I.C., F.C.S. 
 (Paper read before the British Association, Section B, Glasgow, 1901) 
 
 THE coal-tar colour manufacture has well been called the flower 
 of the chemical industries. Although in absolute money value of 
 its products not equalling some other branches of industrial 
 chemistry, it represents the highest development of applied 
 chemical research and chemical engineering, and may well be 
 taken as the pulse of the whole chemical trade. Indeed, a 
 country which allows the most scientific branch of chemical 
 industry to languish cannot expect to maintain pre-eminence for 
 long in any simpler branch of chemical manufacture ; since the 
 skill trained for attacking the difficult problems of organic 
 chemistry is certain sooner or later to be brought to bear on the 
 simpler questions presented in the manufacture of so-called 
 " heavy " chemicals (acids, alkalies, bleach, salts, etc.), and processes 
 hitherto often left to the supervision of foremen will be taken in 
 hand by educated chemists, with consequent improvement in 
 methods of manufacture, better yields, purer products, and cheaper 
 production. The importance of the coal-tar industry cannot 
 therefore be estimated alone by the value of its products, for it 
 exerts a widespread effect upon all other branches of chemical manu- 
 facture, from many of which it draws its supplies of raw material. 
 As a pregnant example of this influence, especially noticeable during 
 the last decade, I may mention the revolution which is taking 
 
 189 
 
1 90 THE BRITISH COAL-TAR INDUSTRY 
 
 place in the manufacture of sulphuric acid, that most important 
 product of the " heavy " chemical trade. A strong demand had 
 arisen in the colour industry for a large and cheap supply of 
 sulphuric anhydride, chiefly in connection with the manufacture 
 of alizarin colours and of artificial indigo. With the object of 
 satisfying their own requirements in this respect, the Baden 
 Aniline and Soda Works of Ludwigshafen devoted much time 
 and research to the problem of improving the catalytic process 
 usually known by the name of Winckler, a modification of which 
 process had been worked in this country by Squire Chapman and 
 Messel since 1876. This endeavour was attended with such 
 success that by means of the process and plant which they finally 
 evolved they were enabled to produce sulphuric anhydride so 
 cheaply that not only could it be used as such for a large variety 
 of purposes, but by combination with water afforded a profitable 
 source of sulphuric acid. This new method of manufacturing 
 sulphuric acid is, for concentrated acid at least, cheaper than the 
 chamber process ; and since the product is absolutely free from 
 arsenic, and can be produced at any desired concentration, it 
 seems likely to supplant eventually the time-honoured method 
 of manufacture. 
 
 Besides exerting this influence upon the inorganic chemical 
 manufactures, the coal-tar industry has given birth during recent 
 years to several important daughter industries. The manufacture 
 of synthetic medicinal agents, artificial perfumes, sweetening 
 materials, antitoxines, nutritives, and photographic developers 
 are all outgrowths of the coal-tar industry, and in great part still 
 remain attached to the colour works where they originated. Of 
 these subsidiary industries the most important is the manufacture 
 of synthetic medicinal preparations, which has already attained to 
 large proportions, and bids fair to revolutionise medical science. 
 The requirements of the coal-tar industry have further led to 
 great advances in the design and production of chemical plant, 
 such as filter-presses, autoclaves, fractionating columns, vacuum 
 pumps and stills, suction filters, enamelled iron, aluminium, and 
 stoneware vessels, etc., for the supply of which extensive works 
 have become necessary. 
 
 It is a frequently quoted remark of the late Lord Beacons- 
 field that the chemical trade of a country is a barometer of its 
 prosperity, and the chemical trade of this country has always 
 been regarded as a most important branch of our manufactures. 
 
PROGRESS DURING FIFTEEN YEARS 1886-1900 191 
 
 Even those who might be inclined to regard our declining 
 position in the colour industry with more or less indifference 
 would consider the loss of a material portion of our general 
 chemical trade as nothing less than a national calamity. As 
 already pointed out, however, the two are indissolubly con- 
 nected, the coal-tar industry being an essential and inseparable 
 part of the chemical industry as a whole. It is with the object 
 of ascertaining our present and future prospects in the chemical 
 trade of the world that 1 propose to compare the relative develop- 
 ment of the colour industry in England and Germany during the 
 past fifteen years. It was at the commencement of this period, 
 that is to say in the year 1886, that Professor Meldola, in a paper 
 read before the Society of Arts, gave such a masterly account of 
 the position of the industry of this country at that date, and 
 sounded a warning note to our manufacturers and business men 
 regarding its future progress. 
 
 If an excuse is required for my venturing to refer again to a 
 subject upon which so much has been said and written already, 
 it is supplied by the fact that the warnings repeatedly given by 
 those who saw the future clearly (notably by Professors Meldola 
 and Armstrong) have remained largely unheeded by our business 
 men. The conclusions which are forced upon us are unfortun- 
 ately not of a reassuring nature for our national trade, but it is 
 well to remember that nothing is gained by burying our heads 
 in the sand, and that the cure of a disease can only be effected 
 after an accurate diagnosis of its cause. 
 
 The period which we have to consider has been one of 
 extraordinary activity and remarkable development in the coal-tar 
 industry, and before I pass to the economic aspect of the question 
 I shall ask you to consider very superficially some of the main 
 points in this advance. In no other industry than this have such 
 extraordinarily rapid changes and gigantic developments taken 
 place in so short a period, developments in which the scientific 
 elucidation of abstract problems has gone hand in hand with 
 inventive capacity, manufacturing skill, and commercial enterprise. 
 In no other industry has the close and intimate interrelation of 
 science and practice been more clearly demonstrated. 
 
 Born in 1856, the colour industry had already attained to a 
 considerable state of development by the year 1886. The period 
 prior to this might well be called the " rosaniline period," since 
 it is chiefly marked by the discovery and development of colour- 
 
192 THE BRITISH COAL-TAR INDUSTRY 
 
 ing matters of the rosaniline or triphenylmethane group, such 
 as magenta, aniline blue, Hofmann violet, methyl violet, acid 
 magenta, acid violets, phosphine, Victoria blues, auramine, 
 malachite green, and acid greens. Individual members of other 
 groups had already been discovered, but the latter had not 
 yet attained to the importance which they were destined later 
 to occupy. This is especially the case with the class of colouring 
 matters containing the double nitrogen radical known as " azo " 
 colours. This group of compounds has, during the fifteen years 
 which we have to consider, attained to such enormous dimensions 
 and importance that this interval may fairly be termed the 
 " azo period." The number of individual compounds belonging 
 to this class, which have either been prepared or are at present 
 preparable, runs into many millions and far exceeds the members 
 of all other groups of colouring matters put together. In 
 commercial importance also they occupy a position at present far 
 in advance of any other group, the employment of some of them 
 (e.g. the " azo " blacks) amounting to many thousands of tons 
 annually. A great stimulus to the investigation of the azo 
 compounds was given by the discovery by Bottiger in 1884 of 
 the first colour possessing a direct affinity for cotton (Congo red), 
 which was followed within a few years by a rapidly increasing 
 series of colours of all shades having similar dyeing properties. 
 The azo colours known prior to this time were either basic 
 colours (aniline yellow, chrysoidine, Bismarck brown, etc.) or 
 acid wool colours (xylidine scarlet, croceine scarlet, etc.). The 
 great simplification of cotton dyeing brought about by the 
 introduction of the new group of azo colours " benzo " or 
 " diamine " colours as they were called led to a rapid increase 
 in their number, and compounds containing two, three, four, or 
 more double-nitrogen groups, linking together the residues of 
 various paradiamines (benzidine, tolidine, dianisidine, azoxy- 
 toluidine, paraphenylenediamine, naphthylenediamine, etc.) to 
 various naphthol-, amidonaphthol-, and naphthylamine sulphonic 
 acids made their appearance in quick succession. Simultaneously 
 therewith proceeded the discovery and investigation of the 
 various isomeric derivatives of naphthalene required as raw 
 products for the preparation of these colours, an investigation 
 which was largely aided by the classical research on the isomerism 
 of naphthalene compounds carried out in this country by Arm- 
 strong and Wynne. 
 
PROGRESS DURING FIFTEEN YEARS 1886-1900 193 
 
 Another method of applying azo colours to cotton, by which 
 much faster shades are obtained, was introduced by Messrs 
 Read Holliday, of Huddersfield, in 1880, and consisted in 
 producing unsulphonated azo compounds on the fibre by direct 
 combination. Owing to the technical difficulties which were at 
 first encountered in applying this process it has only reached 
 its full development during the last few years and at other hands 
 than those of its discoverers. The most important colour 
 produced by this method is paranitraniline red, for which over 
 two hundred tons of chemically pure paranitraniline are manu- 
 factured annually. 
 
 The search for direct cotton colours led the author in 1887 
 to the discovery of primuline. This compound, having a direct 
 affinity for cotton and containing at the same time a diazotisable 
 amido group, could be used for the synthesis of various azo 
 colours on the fibre which were remarkable for great fastness to 
 washing. It has had a large employment for the production 
 of fast reds, and the new principle of dyeing which it introduced 
 has been considerably extended in other so-called " diazo " colours. 
 The closer investigation of the thiazol group, to which primuline 
 belongs, further led to the discovery of many other cotton 
 colours belonging to this family, amongst the most important 
 of which are the brilliant greenish-yellow called turmerine or 
 Clayton yellow, the light-fast chlorophenine or chloramine yellow, 
 the pure greenish basic yellow thioflavine, and the fast cotton 
 pink erica. 
 
 Passing over the stilbene azo colours and the basic azo 
 ammonium or Janus colours, there remains a class of azo com- 
 pounds to which 1 must shortly refer, namely, the mordant 
 azo colours, which with the growing demand for faster shades 
 have recently come into much prominence. In these compounds 
 the presence of an orthohydroxyl or carboxyl group gives to 
 the colour the property (following Liebermann and v. Kosta- 
 necki's rule) of combining with metallic mordants, especially 
 chromium oxide, and producing therewith insoluble and fast 
 lakes on the wool or cotton fibre. 
 
 We now come to the consideration of three analogously 
 constituted groups of colouring matters, namely, the azines, 
 oxazines, and thiazines. The laborious scientific investiga- 
 tions of Fischer and Hepp, Bernthsen, Kehrmann, and others 
 on the constitution of these groups of compounds, the first 
 
 13 
 
194 THE BRITISH COAL-TAR INDUSTRY 
 
 members of which (methylene blue, safranine, and Meldola's 
 blue) were discovered in a very early stage of the industry 
 when little or nothing was known of their structure, combined 
 with the theoretical views on the quinonoid structure of such 
 colouring matters promulgated by Armstrong and adopted 
 by Nietzki, led to the discovery of many valuable new mem- 
 bers of these classes. Amongst the latter may be specially 
 mentioned the rosindulines, indoine blue, induline scarlet, rhodu- 
 lines, etc. 
 
 Passing to the pyrone and acridine groups in which much 
 investigation has also been conducted, the most notable advances 
 have been the discovery of the rhodamines, a class of pure 
 basic reds, and of the basic yellows and oranges allied tc 
 phosphine, namely, acridine yellow, benzoflavine, and acridine 
 orange. 
 
 It is in the alizarin group next to the azo group that the 
 greatest progress must be recorded. The demand for fasl 
 colours for calico printing and for dyeing chrome-mordantec 
 wool to withstand severe " milling " operations has led to c 
 long series of investigations and patents for producing nev^ 
 derivatives of anthraquinone. These new products, known ir 
 commerce as alizarin Bordeaux, alizarin cyanines, anthracene 
 blues, alizarin viridine, alizarin saphirol, etc., are polyoxy- 01 
 amido-oxyanthraquinones, for the preparation of which eithei 
 alizarin or nitroanthraquinones are the usual starting-points. 
 
 Passing over some smaller groups, we now come to a ver) 
 peculiar class of dyestuffs containing sulphur, which although 
 discovered by Croissant and Brettoniere in 1873, remainec 
 confined to a single representative Cachou de Laval, unti 
 Raymond Vidal in 1893 obtained a very fast black colouring 
 matter, which dyed unmordanted cotton, by heating para-amido 
 phenol with sulphur and sodium sulphide. The possibility o 
 replacing aniline black in cotton dyeing by a direct colouring 
 matter, and possibly also of obtaining other shades which, thougl 
 dyed in a single bath, would resist subsequent " cross dyeing ' 
 of the wool in mixed fabrics, lent an immense impulse to th< 
 study of this class of colouring matters ; and although thei 
 molecular structure still remains wrapped in obscurity, man] 
 new representatives have followed each other in rapid succession 
 ranging in shade from blacks of various hues to browns, olives 
 greens, and blues. As the most important of these I 
 
PROGRESS DURING FIFTEEN YEARS 1886-1900 195 
 
 mention Vidal black, immedial black, katigene black, immedial 
 blues, pyrogene blues, katigene brown, katigene green, etc. 
 
 It may fairly be claimed, however, that the greatest triumph 
 of the coal-tar industry for the past fifteen years has been the 
 successful production of artificial indigo on a large manufacturing 
 scale. 
 
 Returning from the scientific to the economic aspect of the 
 subject, I shall ask you now to consider what share we have 
 obtained in the great expansion of trade resulting from all these 
 new discoveries, many of which have originated in this country. 
 The development of the industry in Germany is well illustrated 
 by the following figures : 
 
 EXPORTS FROM GERMANY TO THE WORLD 
 
 
 1885. 
 
 1895. 
 
 1899. 
 
 
 Tons. 
 
 Tons. 
 
 Tons. 
 
 Aniline oil and salt .... 
 Coal-tar colours (excl. alizarin) . 
 Alizarin colours .... 
 
 1713 
 4646 
 4284 
 
 7,135 
 15^89 
 8,927 
 
 !7> 6 39 
 
 Again, if we take values, we find that total exports of coal- 
 tar colours from Germany amounted in 1894 to 2,600,000, 
 and in 1898 to 3,500,000, an increase of nearly a million in 
 four years. The latter figure is practically the same as that 
 given by Per kin as an estimate of the world's total production in 
 1885, showing how great the increase has been since this date. 
 
 The value of Germany's entire production is somewhat 
 difficult to arrive at. Witt, in his report on the German chemical 
 exhibit at the Paris Exhibition, gives as the value of the total 
 chemical industry of Germany for the year 1897 the enormous 
 sum of 46^- million pounds sterling. Of this sum Lef&vre 
 estimates that at least one-tenth may be put down to colouring 
 matters, and another tenth to raw, intermediate, and synthetic 
 products from coal tar other than colours, and he thus assigns 
 for the total annual value of the coal-tar industry of Germany 
 the sum of nine to ten million pounds sterling. With the 
 increase in the production of synthetic indigo, it may be taken 
 to-day to considerably exceed this figure. 
 
196 THE BRITISH COAL-TAR INDUSTRY 
 
 One may well wonder what becomes of this enormou: 
 quantity of coal-tar products. According to the United State; 
 consular reports the 3^ million pounds' worth of coal-tar colour; 
 exported by Germany in 1898 were consumed as follows : 
 
 The United States took .... .750,000 worth 
 The United Kingdom took . . . 730,000 
 Austria and Hungary ... 350,000 
 Italy . . 225,000 
 
 China ,, ... 270,000 
 
 whilst the rest of the world took the remainder. 
 
 The great increase in production in Germany is furthe 
 shown by the growth in the capital and number of workpeopL 
 employed. Thus according to a report of the Badische Works 
 recently issued, the capital of this company, which was increasec 
 in 1889 from 900,000 to 1,050,000, will be further augmente( 
 this year by the issue of 750,000 of debentures. The numbe 
 of workpeople employed by this company in 1900 was 6485, a 
 against 4800 in 1896, an increase of over 33 per cent, in fou 
 years. The firm of Leopold Cassella & Co., of Mainkur, nea 
 Frankfurt, have increased the number of their workpeople fron 
 545 in 1890 to 1800 in 1900. 
 
 Passing now to England, we find that the imports of coal-ta 
 colours into the country are steadily rising, as is shown by th 
 following figures taken from the Board of Trade returns : 
 
 IMPORTS OF COAL-TAR DYESTUFFS INTO ENGLAND DURING THE LAST 
 FIFTEEN YEARS (EXCLUDING INDIGO) 
 
 1886 
 1887 
 1888 
 1889 
 1890 
 
 542,000 
 569,000 
 609,200 
 594,400 
 
 1891 . 
 
 1892 . . 542,200 
 
 1893 . . 504,000 
 
 1894 . . 599,000 
 
 . 710,000 
 
 1896 . 
 
 1897 . . 695,40 
 
 1898 . . 739,00 
 
 1899 . . 708,80 
 
 1900 . . 720,00 
 
 Contrasted with this, the exports of coal-tar colours manu 
 factured in 'England have fallen from 530,000 in 1890 t< 
 366,500 in 1899. Comparing these figures with the rapidl; 
 increasing export trade of Germany, it is seen that wherea 
 formerly the English export trade in artificial colours was abou 
 one-quarter that of Germany, it does not now amount to a tenti 
 part. It is therefore only too apparent that we have had bu 
 little share in the great increase which this industry has experi 
 
PROGRESS DURING FIFTEEN YEARS 1886-1900 197 
 
 enced during the past fifteen years, and that we have not even 
 been able to supply the expansion in our own requirements. In 
 order to ascertain what proportion of our own needs we at present 
 furnish, I am able to lay before you the following interesting 
 figures, which have been kindly supplied to me by the Bradford 
 Dyers 1 Association and the British Cotton and Wool Dyers' 
 Association, who together form a large proportion of the entire 
 dyeing trade : 
 
 COLOURING MATTERS USED BY BRADFORD DYERS' 
 ASSOCIATION 
 
 English, 10 per cent. ; German, 80 per cent. ; Swiss, 6 per 
 cent. ; French, 4 per cent. 
 
 COLOURING MATTERS USED BY BRITISH COTTON AND WOOL 
 DYERS' ASSOCIATION 
 
 Aniline Colours. English, 22 per cent. ; foreign, 78 per 
 cent. 
 
 Alizarin Colours. English, 1-65 per cent. ; foreign, 98*35 
 per cent. 
 
 The English Sewing Cotton Company have also very kindly 
 supplied me with a detailed analysis of their consumption, from 
 which it appears that out of a total of sixty tons of colouring 
 matters and other dyeing materials derived from coal tar only 
 9 per cent, were of English manufacture. 
 
 The following table of statistics of the six largest German 
 firms gives a fair picture of the present dimensions of the 
 industry in that country. 
 
 The joint capital of these six firms amounts to at least 
 i\ millions. They employ together about 500 chemists, 350 
 engineers and other technologists, 1360 business managers, 
 clerks, travellers, etc., and over 18,000 workpeople. Compared 
 with such figures as these the English colour manufacture 
 assumes insignificant proportions. The total capital invested 
 in the coal-tar colour trade in England probably does not exceed 
 500,000, the total number of chemists employed cannot be 
 more than thirty or forty, and the number of workmen engaged 
 in the manufacture does not amount to over a thousand. 
 
198 THE BRITISH COAL-TAR INDUSTRY 
 
 POSITION OF THE Six LARGEST COLOUR WORKS IN GERMANY IN YEAR 1900 
 
 
 
 Badische 
 Aniline 
 Works. 
 
 Meister, 
 Lucius & 
 Bruning. 
 
 Farben- 
 fabriken 
 Bayer 
 &Co. 
 
 Berlin 
 Aniline 
 Co. 
 
 Cassella 
 &Co. 
 
 Farbwerk 
 Mlihlheim, 
 Leonhardt 
 &Co. 
 
 Total of 
 six largest 
 firms. 
 
 Capital 
 
 .1,050,000 
 
 833,000 
 
 882,000 
 
 441,000 
 
 Private 
 
 157,000 
 
 About 
 
 
 
 
 
 
 concern 
 
 
 ^2,500,001 
 
 Number of 
 
 148 
 
 120 
 
 145 
 
 55 
 
 N 
 
 
 About 5oc 
 
 chemists 
 
 
 
 
 
 
 
 
 Number of 
 
 75 
 
 36 
 
 175 
 
 3i 
 
 
 
 About 35C 
 
 engineers, 
 
 
 
 
 
 60 
 
 
 
 dyers, and 
 
 
 
 
 
 
 
 
 other tech- 
 
 
 
 
 
 
 45 
 
 
 nologists 
 
 
 
 
 
 ^ 
 
 
 
 Commercial 
 
 305 
 
 211 
 
 5oo 
 
 150 
 
 170 
 
 
 About 136 
 
 staff 
 
 
 
 
 
 
 
 
 Workpeople 
 
 6485 
 
 3555 
 
 4200 
 
 1800 
 
 1800 
 
 ' 
 
 About 1 8, 2 
 
 
 Per cent. 
 
 Per cent. 
 
 Per cent. 
 
 Per cent. 
 
 
 Per cent. 
 
 
 Dividends in 
 
 24 
 
 26 
 
 18 
 
 I2J 
 
 Not 
 
 9 
 
 
 
 1897 
 
 
 
 
 
 known 
 
 
 
 Dividends in 
 
 5 } 
 
 > j 
 
 ii 
 
 15 
 
 j 
 
 3 
 
 
 
 1898 
 
 
 
 
 
 
 
 
 Dividends in 
 
 
 
 > 
 
 
 
 ii 
 
 ii 
 
 5 
 
 
 
 1899 
 
 
 
 
 
 
 
 
 Dividends in 
 
 
 
 20 
 
 
 
 ? 
 
 > > 
 
 Nil 
 
 
 
 1900 
 
 
 
 
 
 
 
 
 A similar relative proportion is maintained in the number o 
 patents for new colouring matters and other coal-tar product 
 taken by the English and German firms, as is shown by th 
 following table : 
 
 COMPARISON OF NUMBER OF COMPLETED ENGLISH PATENTS FOR COAI 
 TAR PRODUCTS TAKEN DURING 1886-1900 BY Six LARGEST ENGLIS: 
 AND Six LARGEST GERMAN FIRMS 
 
 German Firms 
 
 Badische Aniline Works . . 179 
 Meister, Lucius & Briining . 231 
 Farbfabriken Bayer & Co. . 306 
 Berlin Aniline Co. . . .119 
 L. Cassella & Co. . . -75 
 Farbwerk Miihlheim, Leonhardt 
 & Co 38 
 
 English Firms 
 
 Brooke, Simpson & Spiller 
 
 Clayton Aniline Co. . 
 
 Levinstein . 
 
 Read Holliday & Co. 
 
 Claus & Ree . 
 
 W. G. Thompson . 
 
 To tal of six German firms . 948 Total of six English firms . 8 
 
 Nor does the potential loss which we have sustained by ou 
 inability to take advantage of a growing industry represent th 
 
PROGRESS DURING FIFTEEN YEARS 1886-1900 199 
 
 sum total of our losses. The new colouring matters, made 
 almost exclusively in Germany, have in many cases been intro- 
 duced as substitutes for natural products, which were staple 
 articles of English commerce. Madder and cochineal have been 
 replaced by alizarin and azo scarlets, the employment of many 
 dyewoods has greatly decreased, whilst at the present moment 
 logwood and indigo are seriously threatened. Regarding the 
 indigo question, so much has been written that I do not propose 
 to occupy space in its further discussion, but will only point out 
 that the complete capture of the indigo market by the synthetic 
 product, which would mean a loss to our Indian dependencies of 
 3,000,000 a year, is regarded by the Badische Company as so 
 absolutely certain that, having already invested nearly a million 
 pounds in the enterprise, they are at present issuing 750,000 of 
 new debenture capital to provide funds to extend their plant for 
 this purpose. In the last annual report of the company they 
 say : " As regards plant indigo, the directors are prepared and 
 determined to meet this competition in all its possible variations 
 in value. Much strange matter has been published in India as 
 to improvements in the cultivation and preparation of natural 
 indigo, but the illusions of the planters and indigo dealers are 
 destined to be dispelled before facts, which, although they are 
 not known to them, will make themselves more felt the larger 
 the production of artificial indigo becomes." 
 
 Besides the loss of material wealth which the neglect of the 
 coal-tar trade has involved to the country, there is yet another 
 aspect of the question which is even of more importance than 
 the commercial one. There can be no question that the growth 
 in Germany of a highly scientific industry of large and far- 
 reaching proportions has had an enormous effect in encouraging 
 and stimulating scientific culture and scientific research in all 
 branches of knowledge. It has reacted with beneficial effect 
 upon the universities, and has tended to promote scientific 
 thought throughout the land. By its demonstration of the 
 practical importance of purely theoretical conceptions it has had 
 a far-reaching effect on the intellectual life of the nation. -How 
 much such a scientific revival is wanted in our country the social 
 and economic history of the past ten years abundantly testifies. 
 
 The position with which we are confronted is in truth a 
 lamentable one, and the way out is not so easy to find. In 1886 
 it could perhaps still be maintained that we held the key to the 
 
200 THE BRITISH COAL-TAR INDUSTRY 
 
 situation if we chose to make use of it, inasmuch as the principal 
 raw products of the colour manufacture (tar oils, naphthalene, 
 anthracene, soda, ammonia, iron, etc.) were in great measure 
 imported from England. In a speech to the Academy of Sciences 
 of Munich in 1878 Professor von Baeyer had said : "Germany, 
 which in comparison with England and France possesses such 
 great disadvantages in reference to natural resources, has suc- 
 ceeded by means of her intellectual activity in wresting from 
 both countries a source of national wealth. Germany has no 
 longer to pay any tribute to foreign nations, but is now receiving 
 such tribute from them, and the primary source from which this 
 wealth originates has its home, not in Germany, but in England. 
 It is one of the most singular phenomena in the domain of 
 industrial chemistry that the chief industrial nation and the most 
 practical people in the world has been beaten in the endeavour 
 to turn to profitable account the coal tar which it possesses. We 
 must not, however, rest upon our oars, for we may be sure that 
 England, which at present looks on quietly while we purchase 
 her tar and convert it into colours, selling them to foreign nations 
 at high prices, will unhesitatingly cut off the source of supply as 
 soon as all technical difficulties have been surmounted by the 
 exertions of German manufacturers." 1 Professor von Baeyer 
 could not believe that the English manufacturer and capitalist 
 would stand calmly by and see an important industry which had 
 had its origin and early development in his own country taken 
 from beneath his nose without an effort to retain it. Yet the 
 initial advantages which our natural resources afforded us have 
 been neglected, and now in 1901 the conditions are completely 
 changed. The adaptation of condensing plant to the Westphalian 
 coke ovens has rendered Germany, though still a large buyer 
 from England, no longer dependent on English tar and ammonia ; 
 by the development of the ammonia-soda process she no longer 
 requires English alkali ; whilst all other raw products of the 
 colour industry can now be purchased in the commercial centres 
 of Germany at least as cheaply as in England, and some even at 
 lower prices. Through the shortsightedness, ignorance, and 
 want of enterprise of those with whom the care of the colour 
 industry in this country has rested, the opportunity has been 
 allowed to pass for ever. The English capitalist has passed over 
 as not sufficiently profitable for his consideration an industry 
 1 Quoted by Mr Levinstein, Jour. Soc. Chcm. Ind., 1886, p. 350. 
 
PROGRESS DURING FIFTEEN YEARS 1886-1900 201 
 
 which at present amounts to nine or ten million sterling annually, 
 and from which his German confrere reaps a dividend of nearly 
 20 per cent. The English manufacturer has considered that a 
 knowledge of the benzol market was of greater importance than 
 a knowledge of the benzol theory, and after the early but brilliant 
 days in the infancy of the industry, when guided by such eminent 
 workers as Hofmann, Perkin, and Nicholson, commercial progress 
 and scientific investigation went hand in hand, but little encourage- 
 ment has been given here to chemical investigators and discoverers. 
 The control of the industry unfortunately soon passed into the 
 hands of men who had no knowledge and absolutely no apprecia- 
 tion of the science upon which their business rested, and, con- 
 cerned only with getting the ultimate amount of present profit, 
 discouraged all scientific investigations as waste of time and 
 money. The chemist who devoted himself to the elucidation of 
 the chemical constitution of a colouring matter was regarded by 
 them as an unpractical theorist of no value to a manufacturing 
 business. Even when he discovered new colouring matters of 
 commercial value they were so blind to their own interests, and 
 so incapable of believing that any practical good could come out 
 of such theoretical work, that in many cases they refused to 
 patent or in any way take advantage of the discoveries made by 
 him. During recent years this attitude has certainly undergone 
 considerable modification, and some attempt has been made to 
 call in the aid of the science so long neglected. Certain firms, 
 indeed, must be given the credit of endeavouring to pursue a 
 more enlightened policy, but these attempts have been of a more 
 or less sporadic nature and always directed too much in the 
 expectation of realising immediate financial results. The 
 difficulties which must be encountered in the attempt to regain 
 the lost ground are of necessity very great, and are quite un- 
 appreciated by our business men. It seems, in fact, to have been 
 the opinion of the public and the average financial man that this 
 industry ought to be easily won back by us by the establishment 
 of a few technical schools, the engagement of a dozen chemists, 
 and the investment of a few thousand pounds in new plant, 
 forgetting that the supremacy of our German competitors has 
 been gained by years of patient toil, by the work of hundreds 
 of trained chemists, and by the outlay of millions of capital. 
 Who can be surprised therefore if such expectations have not 
 been realised, and if in spite of some notable successes the general 
 
202 THE BRITISH COAL-TAR INDUSTRY 
 
 position of the colour trade in England at the present day, at a 
 time when even the German trade is suffering from the general 
 depression, looks worse than at any previous period ? During 
 years of stagnation in this country the German manufacturers 
 have been realising large profits, which they have employed in 
 consolidating their businesses, writing off the value of their 
 buildings and plant, and accumulating enormous reserves (the 
 reserve of the Badische Company is over a million pounds) : 
 they have gathered round them perfectly working organisations, 
 comprising enormous staffs of scientifically and practically trained 
 research chemists, factory chemists with highly specialised know- 
 ledge, chemical engineers, dyers, and others ; their travellers 
 and agents are in every part of the globe ; by long manufacturing 
 experience and unremitting endeavour to improve their processes 
 and plant they have brought the yields and quality of their 
 products to such a state of perfection that even when the manu- 
 facture of these products is no longer covered by patents they 
 are able to produce them at a cost price which is impossible to 
 anyone commencing their manufacture ; they have hedged them- 
 selves about with a perfect stockade of many hundreds of patents, 
 have accumulated in their laboratories thousands of intermediate 
 products ready at any time to be subjected to any new treatment 
 or combination which research or theory may suggest as likely 
 to yield new results. By the complete range of colours which 
 they are able to offer in each group of dyestuffs, whether basic 
 colours, acid colours for wool, fast colours dyeing on metallic 
 mordants, diazotisable colours, or direct colours for cotton, and 
 by the invaluable aid and assistance which they can give the 
 dyer in his daily work they are enabled to retain his custom 
 even if it sometimes happens that a better and a cheaper article 
 is offered him by the home producer. 
 
 Where, then, are we to look for an improvement ? Some 
 would find a remedy in the imposition of heavy protective tariffs ; 
 but such tariffs in France have not availed to prevent a similar 
 state of things there, and protection in colouring matters might 
 have a very detrimental effect upon the textile industries of the 
 country. Others expect salvation from the extension of technical 
 schools ; but, laudable as is the aim of these institutions, I cannot 
 see how they can effect much until their raw material is of a very 
 different character from what it is at present, and until the public 
 can be completely disabused of the fallacy that a year or two of 
 
PROGRESS DURING FIFTEEN YEARS 1886-1900 203 
 
 technical training pumped into an ignorant schoolboy will pro- 
 duce a better works chemist than a university course of scientific 
 study laid upon the foundation of a good general education. 
 Mr Levinstein again bases his hopes for the future upon a 
 reform of the patent laws, and seeks to compel all patented 
 processes to be worked in this country. Although I am inclined 
 to believe that a portion of our present troubles has been 
 brought about by bad patent law, framed mainly from an 
 engineering and not from a chemical point of view, which seems 
 specially designed to foster foreign trade at our own expense, 
 yet 1 cannot attribute to this cause a too preponderating influence, 
 and am doubtful whether its removal now would materially 
 improve the position. The remedy for the present state of 
 affairs must of necessity be a slow one, and in my opinion can 
 only be found in a better appreciation of the value of science 
 throughout the length and breadth of the land. Until our 
 Government and public men can be brought to realise the 
 importance of fostering the study of science and of encouraging 
 all scientific industries, until our schools and universities ap- 
 preciate the importance of a scientific education, until the rewards 
 for public services in science are made equal to those in other 
 branches of the public service, so long will science continue to 
 be held in insufficient esteem in our country, and the best and 
 most promising of our rising young men will be deterred from 
 adopting chemistry as a profession. It is not so much the 
 education of our chemists which is at fault as the scientific 
 education of the public as a whole. 
 
XII. : 1901 
 THE INDIGO CRISIS 
 
 (Journal of the Society of Dyers and Colour ists y 1901, p. 157) 
 
 IT is now generally recognised that the threatened replace- 
 ment of natural indigo by the synthetic product is a matter not 
 only of scientific interest, but one which may have far-reaching 
 economic and political consequences ; and mainly on this account 
 the public interest has been aroused to an extent which is very 
 unusual in matters of this character. This has been reflected 
 by questions in Parliament and correspondence in the Times, 
 Nature, and other papers, as well as in the more directly 
 concerned trade journals. 
 
 Another reason for the widespread interest evinced is 
 the very impressive manner in which the problem of the 
 artificial production of indigotin has been attacked. The fact 
 that about ; 1,000,000 has been spent by a single German firm 
 in working out the process and in preparing for the commercial 
 introduction of the product has appealed to the public 
 imagination as a concrete example of German enterprise, and 
 has also led many to realise the magnitude of the interests 
 involved. 
 
 Within the last few years many papers and notes on natural 
 and artificial indigo have appeared in this Journal, and the 
 various aspects of the subject will be more or less familiar to 
 members, but the general interest was greatly intensified by the 
 publication of the lectures delivered by Professor von Baeyer and 
 Dr Brunck at the opening of the Hofmann House in Berlin in 
 October 1900. Von Baeyer's lecture dealt chiefly with the 
 theoretical aspect of the question, while Dr Brunck dealt mainly 
 with the manufacturing and commercial side. 
 
 Dr Brunck's lecture will undoubtedly become historical, and 
 a translation is given almost in extenso : 
 
 204 
 
THE INDIGO CRISIS 205 
 
 THE HISTORY OF THE DEVELOPMENT OF THE 
 MANUFACTURE OF INDIGO 
 
 In 1868 the first complete synthesis of a vegetable colouring 
 matter was accomplished. Graebe and Liebermann had pointed 
 out the path from anthracene to alizarin, and chemical industry 
 hastened to follow that path. Magnificent was the result of 
 this undertaking, and the industry of coal-tar colours gained a 
 victory which justified its further hopes and gave it the courage 
 to direct its efforts toward a still higher goal, namely, the 
 conquest of the oldest and most important of all colouring 
 matters, indigo. 
 
 The observation by Emmerling and Engler, that indigo 
 could be made from orthonitroacetophenone, did not supply 
 chemical industry with an effective base. However, after Ad. 
 Baeyer had added the synthesis of isatin to his previous 
 synthesis of indigo from the former, he discovered, in 1880, 
 his beautiful synthesis of indigo from orthonitrophenylpropiolic 
 acid, and thus, from an industrial point of view, the question 
 of manufacturing indigo synthetically assumed concrete and 
 definite form. 
 
 Orthonitrophenylpropiolic acid is a derivative of cinnamic 
 acid ; the latter could, at that time, be made by means of 
 " Perkin's reaction " from benzaldehyde, and this, since the 
 introduction of malachite green into the arts, had become a 
 product much employed in the coal-tar colour industry, and was 
 easily made from toluene. 
 
 The Badische Anilin- und Soda-Fabrik and the Farbwerke 
 vorm. Meister, Lucius & Brilning, at Hoechst-on-the-Main, 
 acquired Baeyer 's patents, and now, in conjunction with the 
 inventor, they began the technical investigation of the problem, 
 which was destined to occupy a period of more than twenty 
 years. 
 
 The task was begun with enthusiasm, and the phases of 
 the individual syntheses were systematically investigated and 
 studied. Of the circumspection and thoroughness with which 
 the subject was studied in all its aspects, but slight conception 
 is given by the patents subsequently taken out. 
 
 I have before me a tabulation of all the patents bearing on 
 this subject, and it shows that in Germany alone there are 
 152 patented inventions. 
 
206 THE BRITISH COAL-TAR INDUSTRY 
 
 It soon became possible to replace " Perkin's process " of 
 making cinnamic acid by the benzal chloride and sodium acetate 
 process. Through this process, cinnamic acid became a cheap 
 article of manufacture, instead of being an expensive laboratory 
 preparation. But, on the other hand, orthonitrocinnamic acid 
 was at first, comparatively, very expensive. 
 
 On nitrating cinnamic acid according to the methods then 
 in use, only a small portion of the cinnamic acid was converted 
 into the orthonitro compound, while the greater part was 
 converted into the paranitro derivative, which is not available 
 for the production of indigo. 
 
 It was, therefore, necessary to alter this unfavourable result, 
 and by employing cinnamic acid ester in place of the free acid, 
 it was possible to so conduct the operation that 70 per cent, of 
 the acid could be converted into the orthonitro compound. 
 
 The subsequent bromination of the orthonitrocinnamic acid, 
 as well as the conversion of the resulting dibromide of this 
 acid into orthonitrophenylpropiolic acid, still offered many 
 difficulties. But the investigations were carried on with 
 enthusiasm and with energy, and, as early as the spring of 1881, 
 they had so far progressed that it was possible to continously 
 manufacture the " propiolic acid." 
 
 This process, however, was not available for the direct 
 manufacture of indigo, because of the high cost of production, 
 which, in spite of ease of execution and of good yields, exceeded 
 that of the vegetable product. 
 
 However, attempts were made in other directions to render 
 " propiolic acid " of use in the arts. 
 
 At that time indigo printing was a secret of but few firms, 
 and was an operation requiring much experience. This 
 circumstance suggested the conversion of "propiolic acid" 
 into indigo upon the fibre, and this conversion was possible after 
 Caro had discovered in sodium xanthate a reducing agent 
 suitable for this purpose. 
 
 " Propiolic acid " was introduced into cotton printing, and 
 was employed especially for the production of those delicate 
 patterns which had hitherto been produced by means of indigo, 
 according to the then prevailing methods, but only with difficulty. 
 Unfortunately, however, this success was more of a theoretical 
 than of a practical nature, for " propiolic acid " was never used 
 generally. 
 
THE INDIGO CRISIS 207 
 
 Although the results of this painstaking labour did not fulfil 
 the expectations of the workers, this fact did not shake their 
 confidence nor diminish their activity. They recognised in the 
 results and the experience so far collected, a foundation upon 
 which it was possible to base further work. 
 
 The year 1882 brought with it Baeyer and Drewsen's 
 synthesis of indigo from orthonitrobenzaldehyde and acetone. 
 This process, which likewise passed into the possession of the 
 Farbwerke, at Hoechst, and of the Badische, was, in turn, 
 subjected to technical investigation. The formation of indigo 
 was, indeed, more smooth than by means of the cinnamic acid 
 process, but the development of a rational method of manufacture 
 of orthonitrobenzaldehyde was beset with difficulties which at 
 first appeared insurmountable. 
 
 After it had been determined that, in spite of the greatest 
 possible variations of the conditions observed, the direct nitra- 
 tion of benzaldehyde yielded only insufficient amounts of the 
 orthonitro derivative, which was accompanied by metanitro- 
 benzaldehyde, which is useless for indigo manufacture, ortho- 
 nitrobenzyl chloride was employed as the initial material for the 
 production of orthonitrobenzaldehyde ; this orthonitrobenzyl 
 chloride is formed along with the paranitro body by the nitra- 
 tion of benzyl chloride, but again, only in subordinate quantities. 
 All attempts to arrive at a better result failed. 
 
 There now remained the possibility of converting ortho- 
 nitrotoluene into orthonitrobenzaldehyde, either by chlorination 
 and subsequent oxidation, or by direct oxidation. These experi- 
 ments were carried on for years, but the difficulties in the way 
 of completely chlorinating orthonitrotoluene, and satisfactorily 
 working up the chlorination product could not, for the time being, 
 be overcome. 
 
 When, in 1886, the Badische Anilin- und Soda-Fabrik had 
 found the method, which has recently also been patented by the 
 Societe des Usines du Rh6ne ancien. Gilliard, Monnet and 
 Cartier, of directly oxidising methyl derivatives of benzene to the 
 corresponding aldehydes, without intermediate conversion into 
 chlorination products, hope was again entertained of arriving at 
 orthonitrobenzaldehyde by oxidising orthonitrotoluene. How- 
 ever, these experiments were unsatisfactory and appeared to be 
 without a practical future. The probability that orthonitro- 
 benzaldehyde would serve as a starting-point for the synthetic 
 
2o8 THE BRITISH COAL-TAR INDUSTRY 
 
 production of indigo became more and more remote. The cost 
 of production of synthetic indigo was not only dependent upon 
 the price of toluene, which was available in but limited quantity, 
 but also upon the utilisation of the paranitro by-product. 
 
 In 1893 the synthesis of indigo from orthonitrobenzaldehyde 
 was made technically available by Kalle & Co., in a manner 
 similar to the way in which the " propiolic acid " process had 
 already been applied. This firm succeeded in converting the 
 intermediate product arising during the formation of indigo 
 from the aldehyde and acetone, namely, orthonitrophenyllacto 
 ketone, into a soluble bisulphite compound, and this found 
 application in printing. This product, which Kalle & Co. have 
 placed upon the market as " indigo salt," is employed for the 
 purposes of printing indigo upon cotton, and is superior to 
 " propiolic acid," on account of the ease of its application. 
 
 It almost seemed as though the investigation of this branch 
 of the subject had ceased. Several years passed by, during which 
 not a single new observation or fact connected therewith was 
 published. It was not until 1896, and when, indeed, it seemed 
 extremely likely that we should solve the problem of a technical 
 indigo synthesis along lines which we had followed in the mean- 
 time, that it appeared from published patents that this apparently 
 abandoned field had, nevertheless, been assiduously cultivated. 
 The Farbwerke, at Hoechst, had arrived at a technically useful 
 process of converting orthonitrotoluene into orthonitrobenzal- 
 dehyde by treating the mixture of products obtained on 
 chlorinating orthonitrotoluene with aniline or aniline sulphonic 
 acid, and which can then be readily isolated. The product so 
 obtained is converted into the corresponding benzylidene com- 
 pound, which latter, on treatment with acids, is converted into 
 orthonitrobenzaldehyde, and aniline or aniline sulphonic acid. 
 
 The method of producing orthonitrobenzaldehyde by direct 
 oxidation of orthonitrotoluene to its aldehyde has since been 
 further developed by the Socit des Usines du Rh6ne, as well as 
 by us, the Badische Anilin- und Soda-Fabrik, and now yields 
 better results. 
 
 While it is thus possible to produce orthonitrobenzaldehyde, 
 the conditions for the manufacture of indigo from this substance 
 are, at present, so far favourable, that, on account of the increased 
 consumption of paranitrotoluene during the last few years, there 
 has arisen a corresponding surplus of orthonitrotoluene as a by- 
 
THE INDIGO CRISIS 209 
 
 product. But the amount of indigo which could be manufactured 
 therefrom would necessarily be confined to narrow limits, and 
 could constitute but a small part of the consumption. 
 
 If, however, this branch of chemical industry were so situated 
 as to be able to entirely disregard the utilisation of the paranitro 
 by-product, yet its ability to expand and to increase would 
 always be circumscribed, and its foundation would be uncertain, 
 so long as its initial material, toluene, is available in but limited 
 quantity. 
 
 Permit me, in explanation of the foregoing, to call your 
 attention to some statistical figures. Benzene and toluene are 
 principally used in the manufacture of coal-tar colours, and their 
 intermediate products, and their annual production is at present 
 about 25,000 to 30,000 tons. On an average, there will be pro- 
 duced about four parts of benzene for every one part of toluene. 
 Consequently, there are annually available about 5000 or 6000 
 tons of toluene, which are just about sufficient to satisfy the 
 present needs. The market value of toluene is, as against 
 previous years, considerably higher than that of benzene, and 
 with increasing demand for toluene, its market value must rise, 
 so long as the amount of available toluene, which is regulated by 
 the demand for benzene, does not increase. 
 
 The toluene now on the market not being available for the 
 manufacture of indigo, it would be necessary to obtain a new 
 supply of toluene. 
 
 This would mean that for every ton of toluene thus obtained, 
 four tons of benzene would have to be made ; some use would, 
 therefore, have to be found for this benzene. 
 
 According to a recent published statement concerning the 
 yield of indigo from toluene, by the newest and best technical 
 methods, one pound of indigo requires about four pounds of 
 toluene. Therefore, the total amount of toluene now produced 
 would suffice, at most, for the production of one-quarter of the 
 world's consumption of indigo, which may be estimated at about 
 1 1,000,000 pounds of 100 per cent, strength ; that is, it would be 
 necessary to add to the present production of coal-tar hydro- 
 carbons four times the amount which is made at present, in order 
 to completely replace vegetable indigo. 
 
 On account of this state of affairs, we have for a long time 
 had but little hope that the indigo syntheses which I have so far 
 discussed could ever be capable of producing indigo in large 
 
 14 
 
210 THE BRITISH COAL-TAR INDUSTRY 
 
 quantity, i.e. completely replacing vegetable indigo. It was, 
 therefore, necessary for us to direct our efforts towards obtaining 
 an indigo synthesis which was based upon an easily accessible 
 initial material, and, above all, an initial material whose supply 
 was sufficient and adequate. 
 
 It was then that is, in 1890 that the chemical world was 
 astounded by the discovery of Heumann, namely, that indigo 
 could be obtained by melting phenylglycocoll with caustic potash. 
 
 Through this discovery, the question of the technical produc- 
 tion of indigo was placed upon a new basis ; the efforts of the 
 industry in this direction were, by this means, led into new 
 and promising paths. Promising, because this new synthesis 
 fulfilled the first requirement of manufacture on a large scale, 
 namely, the cheap and easy production of the required initial 
 materials which, in this case, were solely aniline, acetic acid, 
 chlorine, and alkali. 
 
 This invention was likewise acquired by the Badische Anilin- 
 und Soda-Fabrik, and the Farbwerke at Hoechst, who at once 
 took up the technical investigation of this subject, at first with 
 the assistance of the inventor, but he, unfortunately, died in 
 1894, and so did not see the completion of the structure founded 
 upon his last researches. 
 
 Although the Heumann synthesis fulfilled the first require- 
 ment for technical availability, namely, the easy supply of the 
 initial materials, nevertheless it did not satisfy the requirements 
 with respect to the yield of dyestuff. Although, after numberless 
 experiments, it was possible to improve this yield, yet the im- 
 provement was not such as to make manufacture profitable. 
 
 Experiments to obtain a more satisfactory formation of indigo 
 by substituting for the alkali-melt another condensation agent, 
 led us, and later also the Farbenfabriken vorm. Friedr. Bayer 
 & Co., at Elberfeld, to the observation that an indigo-sulpho 
 acid could be obtained from phenylglycocoll by the action of 
 fuming sulphuric acid. However, this sulpho acid does not 
 possess the good dyeing properties which are possessed by the 
 sulpho acid obtained by the sulphonation of indigo, and this 
 process likewise remained without technical application. 
 
 The hopes which had been placed in phenylglycocoll as the 
 basis for an indigo synthesis proved vain. 
 
 Other glycocolls behaved similarly to phenylglycocoll. Tolyl-, 
 xylylglycoll, and the glycocolls of the naphthylamines yielded 
 
THE INDIGO CRISIS 211 
 
 scarcely any colouring matter, or such small amounts that it was 
 impossible for them to come into consideration at all. Further, 
 it had been ascertained that the derivatives of indigo were inferior 
 to indigo itself, so far as beauty of shade is concerned, and did 
 not meet the demands of the dyer. 
 
 But Heumann had also found that the glycocoll of anthranilic 
 acid, that is, phenylglycocoll-orthocarboxylic acid, likewise yields 
 indigo when treated in a similar manner. In this case the forma- 
 tion of indigo takes place far more smoothly, and experiments 
 soon made it appear that this process was capable of development 
 and perfection. But the industrial realisation of this synthesis, 
 for which the production of anthranilic acid as initial material 
 was needed, involved conditions far less favourable than those 
 for the production of phenylglycocoll, and was beset by extra- 
 ordinary difficulties, which at times appeared insurmountable. 
 These could be cleared away only by men who, in addition to 
 possessing a thorough and a broad chemical knowledge, likewise 
 possessed great technical skill, and who were experienced in 
 solving difficult chemical problems, organic as well as inorganic, 
 attacking them with persistence and with ingenuity, and finally 
 bringing them to a successful issue. Fortunately, we had the 
 assistance of such men, and after almost seven years of labour 
 we succeeded in solving the problem. 
 
 This now brings me to a discussion of the development of 
 the process of manufacturing indigo as it is to-day carried on by 
 us. Phenylglycocoll- or thocarboxylic acid is produced from 
 anthranilic acid and monochloracetic acid. For the manufacture 
 of the former we were at first dependent upon orthonitrotoluene ; 
 orthonitrotoluene could be oxidised to nitrobenzoic acid, and 
 this could then be reduced, or the operations could be reversed, 
 and the reduction product of orthonitrotoluene, namely, ortho- 
 toluidine, could be oxidised in appropriate manner (e.g. by means 
 of its acetyl compound) to anthranilic acid. This process, however, 
 was beset by the same obstacles as was the manufacture of indigo 
 from orthonitrobenzaldehyde. But this was not to prove fatal, 
 for there was a process available, which had been discovered in 
 1890 by HoogewerfF and Van Dorp, and which, starting from 
 phthalic acid, produced anthranilic acid. It was A. W. von 
 Hofmann who, by his gifted investigation of the peculiar action 
 of alkaline solutions of bromine upon amines, furnished these 
 investigators with the basis for their researches. They succeeded 
 
212 THE BRITISH COAL-TAR INDUSTRY 
 
 in converting phthalimide into anthranilic acid by means of an 
 alkaline solution of bromine. 
 
 With phthalic acid as initial material for anthranilic acid, 
 naphthalene became the initial material of the indigo synthesis, 
 and this fact created the first reliable basis for indigo manufacture 
 on a large scale. 
 
 From this time on I was firmly convinced that the path which 
 was now being followed must lead to the achievement of the 
 great object : The replacement of vegetable indigo by synthetic 
 indigo. 
 
 In fact, naphthalene is an initial material which, for the pur- 
 pose of indigo manufacture, is available in unlimited quantities. 
 Based upon reliable information, I estimate that the amount of 
 coal tar which is annually treated for its contained hydrocarbons, 
 and which I assume to be two-thirds of the total world's output, 
 contains from 40,000 to 50,000 tons of naphthalene, and of this 
 only about 15,000 tons, which correspond to the present-day 
 consumption, are isolated. For the purposes of indigo manu- 
 facture, therefore, there remain at least 25,000 tons of naphthalene 
 which hitherto, on account of lack of market, were burned to 
 lamp-black or remained dissolved in the heavy oils, but which 
 can also be isolated by the same means and at the same cost as 
 the aforementioned 15,000 tons. 
 
 The naphthalene in this way available is, however, more than 
 sufficient to cover the amount required for the manufacture of 
 the world's consumption of indigo. 
 
 The auspices for the solution of this great problem were 
 therefore favourable, and it became necessary to bring to bear 
 upon its accomplishment all the ability and energy and all the 
 expedients and means known to the present-day industry, and to 
 make use of all the experience which had been acquired in manu- 
 facturing operations in the course of a great number of years, 
 and to spare no labour and no expense in order to make every- 
 thing, which could possibly contribute to its success, serviceable 
 to this undertaking. 
 
 And, in fact, there was a great work still to be performed. 
 The systematic investigation of the individual phases of the 
 process occupied the attention and activity of our best men 
 through many years. 
 
 We did, indeed, at that time possess the best process then 
 known for the manufacture of phthalic acid. This consisted in 
 
THE INDIGO CRISIS 213 
 
 the oxidation of naphthalene by means of chromic acid, and it had 
 been first developed and perfected by us, and had been in opera- 
 tion for twenty years. But, since phthalic acid so produced was 
 still too expensive, and it was not to be expected that this method 
 of manufacture which had been employed by us for so long a 
 time was still susceptible of an essential improvement, it was 
 necessary to bring about the oxidation of naphthalene by a 
 cheaper means. 
 
 Our chemist, E. Sapper, succeeded in finding an entirely new 
 method for the production of phthalic acid, which consisted in 
 heating naphthalene with highly concentrated sulphuric acid. 
 
 A most comprehensive series of experiments was carried out 
 to develop this process to practical utility. The effect of addi- 
 tions of the most various kinds to the reaction mass was tried, 
 and, in the end, mercury was found to be an agent which brought 
 the yields to a satisfactory point. Even though an accident, 
 namely, the destruction of a pocket containing mercury, was an 
 assistance, this accident merely hastened the solution of the 
 problem. But without it the object would certainly have been 
 achieved. 
 
 On a small scale, the results were perfect. But the manu- 
 facture on a large scale required enormous efforts, much time and 
 patience, and the question of apparatus especially required many 
 and very expensive experiments for its solution. 
 
 In the first place, the oxidation of the naphthalene required 
 large amounts of strong sulphuric acid, and the nearly complete 
 and most advantageous recovery of this was the prime condition 
 of success. Had we been compelled to accomplish this regenera- 
 tion of the sulphuric acid in lead chambers, then this new process 
 would hardly have offered any advantages over the chromic-acid 
 process. 
 
 It was at this stage that our new sulphuric-acid process, which 
 was developed by R. Knietsch, stood us in good stead. The 
 contact process, which had become available for the industrial 
 production of fuming sulphuric acid, through the suggestion of 
 C. Winkler, in 1875, has since been developed by us so that 
 the production of sulphuric anhydride, by the direct union of 
 pyrites burner gases that is, of sulphur dioxide and the oxygen 
 of the air, has now become more profitable for the manufacture 
 of sulphuric acid than is the lead-chamber process. This has 
 been published both in chemical literature and in our patents. 
 
2i 4 THE BRITISH COAL-TAR INDUSTRY 
 
 Our new process of making phthalic acid was, therefore, 
 directly dependent upon this sulphuric acid manufacture, since 
 the latter made it possible to directly convert the sulphur dioxide 
 arising from the oxidation of the naphthalene into concentrated 
 sulphuric acid in the cheapest possible manner. 
 
 You may be able to form an idea as to the part which this 
 sulphuric-acid manufacture plays in our process from the fact 
 that, from our present production of phthalic acid, there result 
 annually 35,000 to 40,000 tons sulphur dioxide which we must 
 reconvert into sulphuric anhydride. For this purpose a plant of 
 about the same size is required as for an equal weight of iron 
 pyrites. 
 
 Now, and only now, was the cycle of the process completed. 
 The oxygen of the air now converts naphthalene into phthalic 
 acid in the cheapest manner possible, and our new sulphuric-acid 
 process thus becomes one of the foundations of indigo manu- 
 facture. This is a firm foundation ! 
 
 While these labours, which extended from 1891 until 1897, 
 were in progress, the manufacture of the other initial materials 
 was investigated and worked out with the same energy. 
 
 Large amounts of chlorine are required in the manufacture 
 of the requisite amount of chloracetic acid, and also for the 
 oxidation of phthalimide to anthranilic acid, and it was therefore 
 necessary to create a cheap source of chlorine. Even now we 
 must chlorinate 4,400,000 Ib. of glacial acetic acid an amount 
 of acetic acid equivalent to 130,000 cubic yards of wood ! 
 Neither Weldon's process nor Deacon's process would answer 
 our purpose ; the former, because the chlorine it yielded was too 
 expensive, and the latter, because its chlorine was too dilute. 
 
 In the meantime, however, the researches on the electrolytic 
 production of chlorine from alkali chlorides had made consider- 
 able strides. A number of electrolytic processes were, indeed, 
 known by name, but their real value was not known, and it was 
 therefore necessary to select from these that process which was 
 best adapted to the requirements of indigo manufacture ; and, 
 since great expenditure is involved in plant of this nature, it was 
 necessary to exercise the greatest caution in this selection. 
 
 We believe that we are justified in holding that, through 
 acquiring the process of the Chemische Fabrik Elektron in 
 Griesheim-on-the-Main, we possess the best process of the 
 present day. 
 
THE INDIGO CRISIS 215 
 
 Only in point of purity the resulting chlorine did not satisfy 
 our high requirements, and here our process for the liquefaction 
 of chlorine enabled us to convert it into its purest form. The 
 development of the process for the production of chloracetic acid 
 was also a difficult task ; however, this branch of manufacture, 
 which, at first, was most disagreeable, has finally developed into 
 a comparatively simple manufacturing operation. 
 
 The manufacture of phthalimide, of anthranilic acid, and of 
 phenylglycocoll-orthocarboxylic acid itself, the real mother-sub- 
 stance of indigo, was more difficult than it at first appeared to be. 
 Whole series of systematic experiments had to be carried out, in 
 order to determine the conditions under which it was possible to 
 obtain a maximum yield of pure acid. 
 
 One of the most difficult problems was the proper carrying 
 out of the melting process on the large scale ; that is, the con- 
 version of phenylglycocoll-orthocarboxylic acid, by heating it 
 with alkali, into the leuco compound which, on oxidation with 
 air, yields indigo. These experiments, in the execution of which 
 R. Knietsch, the able and successful manager of our indigo de- 
 partment, and P. Seidel took most active part, were carried on 
 for years. New apparatus had to be invented and constructed 
 before the process was so far developed as to be adapted for 
 continuous manufacture. 
 
 It may be mentioned, in passing, that during the determina- 
 tion of those conditions which would bring about a satisfactory 
 course of the melting operation, free indoxylic acid was manu- 
 factured which, under the name " indophor," has found applica- 
 tion in cotton printing, namely, for the production of indigo 
 upon the fibre in a manner similar to that in which " propiolic 
 acid " and " indigo salt " are employed. 
 
 The indigo which is obtained from the water solution of this 
 melt, by means of air, is crystalline. In those cases where an 
 especially fine state of division is desired, such as in the fermenta- 
 tion vat, the so-obtained indigo is converted into a sulphate by 
 means of sulphuric acid, and this is decomposed with water, and 
 is thus reconverted into the original indigo in the form of a loose 
 powder, which is extremely easily soluble in the vat. 
 
 I have attempted to present to you, in a short sketch, the 
 history of the development of a new manufacture, and it now 
 devolves upon me to more clearly bring out a few considerations 
 which may be adapted to indicate, at least, the influence of this 
 
216 THE BRITISH COAL-TAR INDUSTRY 
 
 manufacture upon the development of important industries, as 
 well as upon future economic changes. 
 
 The advantages which the synthetic product possesses over 
 the vegetable product have been presented so frequently on other 
 occasions, that in this direction I can be very brief. 
 
 The uniformity and the constant strength of synthetic indigo, 
 its absolute freedom from foreign admixture, its easy reducibility 
 when finely divided, and the ease of application which is thereby 
 secured for the dyer, are to be mentioned as its principal ad- 
 vantages, as against the constantly varying strength and the 
 difficult reducibility of the commercial brands of vegetable indigo. 
 These advantages free the dyer from oppressive dependence upon 
 the dealers, because, on account of lack of methods of accurate 
 determination, he has been obliged to purchase his stock, not 
 according to its actual value, but according to external and 
 easily misleading characteristics. These advantages of the 
 synthetic product now guarantee him absolute uniformity and 
 perfect quality. 
 
 In spite of these advantages, synthetic indigo had to over- 
 come many obstacles which were placed in the way of its intro- 
 duction. It was but natural that its quality was discredited by 
 those to whose interest it was to do so ; this was done, for 
 example, by stating that the impurities contained in vegetable 
 indigo, and which were absent from the synthetic product, were 
 essential to the dyeing process. Again, it was claimed that the 
 indigo which we brought into commerce was nothing more nor 
 less than refined vegetable indigo ! 
 
 One of the greatest obstacles in the way of its introduction, 
 however, was the fact that the conception of a "chemical 
 individual " is for the most part unknown to those who are not 
 chemists. It was impossible for such to comprehend the fact 
 that two bodies of different origin, such as vegetable indigo and 
 synthetic indigo, could be identical ; synthetic indigo was 
 designated as a substitute and adulterant of vegetable indigo, 
 and it was attempted to place it on the same plane with those 
 aniline dyestuffs that dye a similar shade. 
 
 But such deceptions and carpings could not long prevail 
 against the facts. 
 
 Synthetic indigo, in accordance with its very great purity, 
 yields brighter shades. Curiously enough, this circumstance also 
 acted at first, though of course only in isolated instances, as an 
 
THE INDIGO CRISIS 217 
 
 obstacle to its introduction ; thus, for example, one or two of the 
 German military authorities raised an objection because cloth 
 dyed with our pure indigo possessed a somewhat brighter shade 
 than did cloth which had been dyed according to the old method, 
 with impure indigo, and which served as the standard of 
 comparison. 
 
 On account of its easy reducibility and uniformity, dyeing 
 with pure indigo has become an operation equal in ease and 
 simplicity with the dyeing with any other ordinary dyestuff, 
 whilst, formerly, it was only possible after acquiring considerable 
 experience by prolonged practice to obtain a desired shade 
 with certainty, when using vegetable indigo, which, as is known, 
 is available only in brands of the most varying degrees of 
 purity. This latter art, which is often inherited from genera- 
 tion to generation, has lost much of its value through synthetic 
 indigo, and on this account the new product was accorded a 
 most unfriendly reception by many an indigo dyer who was 
 conscious of his own especial skill. 
 
 When, in July 1897, we had succeeded in so far reducing 
 the cost of manufacture of synthetic indigo that we could suc- 
 cessfully compete with the lowest price which vegetable indigo 
 had ever reached, we decided to first erect a plant which would 
 enable us to supply the consumption of this colouring matter 
 in Germany, and in so doing arrangements were made so that, 
 in case of success, our capacity could be increased at will. 
 
 As we were ignorant as to how cheaply the planters could 
 supply vegetable indigo in the course of the impending conflict, 
 and also because there is a possibility that a cheaper and simpler 
 process for the manufacture of indigo might be found, our 
 venture was subject to a very great risk ; because, for its suc- 
 cessful prosecution, extraordinary financial resources were 
 necessary, and, as a matter of fact, we have, to-day, invested 
 about 900,000 for this purpose. 
 
 Up to the present, the results which we have achieved 
 correspond to our expectations, and we hope to be victorious in 
 the long and arduous struggle that is before us. 
 
 Formerly, the value of the indigo annually produced was 
 estimated at 4,000,000 to 5,000,000 ; even at the present 
 prices, which are essentially lower, the value may still be 
 2,500,000 to 3,000,000. 
 
 Although, up to the present, we have succeeded in securing 
 
218 THE BRITISH COAL-TAR INDUSTRY 
 
 to German industry but a part of this sum, and thereby making 
 the German consumer independent of foreign countries, and in 
 retaining for Germany those sums of money which have hitherto 
 been paid to foreigners for indigo, yet it is probably merely a 
 question of time when the entire consumption of indigo will 
 be provided for synthetically, and thus large sums will pass from 
 foreign countries to Germany. 
 
 The quantity of indigo which we produce annually, even at 
 this date, would require the cultivation of an area of more than 
 a quarter of a million acres of land (390 square miles) in the 
 home of the indigo plant. The first impression which this fact 
 may be likely to produce is that the manufacture of indigo 
 will cause a terrible calamity to arise in that country ; but 
 perhaps not. If one recalls to mind that India is periodically 
 afflicted with famine, one ought not, without further considera- 
 tion, to cast aside the hope that it might be good fortune for 
 that country if the immense areas, now devoted to a crop which 
 is subject to many vicissitudes and to violent market changes, 
 were at last to be given over to the raising of breadstuff's and 
 other food-products. For myself, I do not assume to be an 
 impartial adviser in this matter, but, nevertheless, I venture to 
 express my conviction that the Government of India will be 
 rendering a very great service if it should support and aid the 
 progress, which will in any case be irresistible, of this impending 
 change in the cultivation of that country, and would support 
 and direct its methodical and rational execution. 
 
 I have reached the end of my lecture. You have seen that 
 this new industry is not an unexpected gift fallen from the 
 heavens, but that in order to complete the task the intellectual 
 labour and the industry of many men had to be co-ordinated, 
 in an organised attempt to attain a definite object, for a number 
 of years, and throughout a considerable period when success 
 could by no means be regarded as certain. The pre-requisites 
 for practical indigo synthesis were supplied by the results of 
 long years of scientific labour. All the expedients of an ad- 
 vanced art were at command, and it is to the wide knowledge, to 
 the industry, to the energy, and to the faithfulness to duty which 
 characterise our German chemists that the final completion of 
 the work is due, a work of which we wish that it may signify an 
 advance in civilisation, and which we hope will be an honour to 
 the German chemical industry and a blessing to our country. 
 
THE INDIGO CRISIS 219 
 
 OTHER OPINIONS 
 
 In a recent lecture before the Society of Arts, 1 Professor 
 Meldola discussed the various synthetical processes for the 
 manufacture of indigo, and more especially the manufacture of 
 " indigo pure " by the Badische Aniline Co. 
 
 With regard to the all-important point of cost of production, 
 Professor Meldola offers the following remarks : " Naphthalene 
 is the hydrocarbon which exists in coal tar to a larger extent than 
 any other. The average quantity is about 8 per cent., and there 
 is any amount of it to be had. The whole of the naphthalene in 
 tar is not at present extracted, the chief supply being furnished 
 by the middle or carbolic acid fraction. Mr T. Wilton, of the 
 Gaslight and Coke Co., states that that company produces about 
 19^- million gallons of tar annually. This company alone would 
 thus be able to supply over 15 million pounds of naphthalene 
 per annum. The purified hydrocarbon has a present market 
 value of 18, los. per ton, which is less than one penny per 
 pound. From an estimate supplied by Mr Charles Tyrer, of 
 Thomas Tyrer & Co., it appears that technical chloracetic acid 
 might probably be made at about is. id. per pound. As regards 
 the supply of naphthalene, it has been suggested that the pro- 
 duction from coal tar would be insufficient to meet the demand, 
 supposing that all the indigo now required were made syntheti- 
 cally." Figures given by Dr Brunck refute this statement. 
 (See page 212.) 
 
 It may be added also that coal tar is not the only source of 
 naphthalene, since a considerable quantity of this hydrocarbon 
 is contained in coke-oven tar. Moreover, petroleum may be 
 looked upon as a potential source of naphthalene, since the 
 crude naphtha, consisting chiefly of heptane and octane, on 
 decomposition by heat, gives a mixture of hydrocarbons con- 
 taining, according to Worstall and Burwell, 2 12*5 parts benzene, 
 3 parts toluene, 3 parts xylene, and 3*6 parts naphthalene for 
 100 parts naphtha. 
 
 With respect to the probabilities of the issue of the conflict 
 between natural and synthetic indigo, Professor Meldola, while 
 not regarding the cause of the indigo planters as a forlorn one, 
 
 1 Jour. Soc. Arts, iQth April 1901. 
 
 2 Amer. C hem. Jour., 1897, x. 815. 
 
220 THE BRITISH COAL-TAR INDUSTRY 
 
 considers the outlook as gloomy, in view of the probability of 
 the Badische process being still further perfected and cheapened. 1 
 
 The magnitude of the operations of the large German colour 
 works has often been the subject of remark in these columns, 
 but their remarkable growth and the unbounded enterprise with 
 which they are conducted is very succinctly put in the following 
 paragraph from Professor Meldola's lecture : 
 
 " The factory at Ludwigshafen employs 148 scientific chemists, 
 75 engineers and technical experts, and 303 members of the 
 mercantile staff. In 1865 they commenced with 30 workmen, 
 and they now employ 6000. The consumption of coal is about 
 243,000 tons per annum. Water is supplied to the factory to 
 the extent of 20,000,000 cubic metres (4,400,000,000 gallons) 
 annually ; they make 12,000,000 kilograms (11,400 tons) of ice, 
 and 12,000,000 cubic metres (420,000,000 cubic feet) of coal 
 gas in the course of a year. 102 boilers supply steam, which 
 serves for heating purposes and for driving 253 steam engines. 
 The factory comprises an area of 206 hectares (510 acres), of 
 which 317,429 square metres (378,000 square yards) are built 
 upon." 
 
 In October of last year a Commission was appointed by the 
 Government of India to inquire into the condition of the sugar 
 and indigo industries, and their report, which has already been 
 issued, is reviewed in the Times of I5th April 1901. It is there 
 stated that the average acreage in India under indigo during the 
 five years 1893-98 was 1,406,000 acres, but in 1899 it was only 
 1,027,000 acres, and in 1900, 964,000 acres. In 1895-96 the 
 exports amounted to 187,000 cwts., but steadily declined to 
 1 1 1,000 cwts. in 1899-1900. This was partly due to unfavour- 
 able seasons ; but in the past experience of the trade, a low output 
 was always accompanied by an enhanced price ; whereas, in the 
 period referred to, the price in the poor years did not show the 
 same recovery, and the Commissioners conclude that it is reason- 
 able to anticipate that the competition of synthetic indigo will 
 prevent any future increase in the price of vegetable indigo, 
 and that any further reduction in price would be ruinous to the 
 planters in a bad season. 
 
 On the other hand, the planters, who take a more sanguine 
 view than the Commissioners, consider that by improved culti- 
 
 1 An interesting discussion of this point will be found in a paper by 
 Dr Levinstein (see Jour. Soc. Dyers and Colourists, 1901, p. 138). 
 
THE INDIGO CRISIS 221 
 
 vation and mode of extraction and manufacture, a greatly increased 
 yield will enable them to place a much improved article on the 
 market at a cheaper rate. This side of the question is well 
 argued in Mr Rawson's paper, read before a meeting of planters 
 and merchants in Calcutta, and abstracted in the Journal of the 
 Society of Dyers and Co tourists (1901, p. 103). 
 
 Under the title of " The Downfall of Natural Indigo," Pro- 
 fessor Armstrong, on 1 5th April, published a long letter in the Times 
 discussing Dr Brunck's lecture. He takes it pretty much for 
 granted that the indigo industry is doomed to rapid extinction, 
 and makes this a text for a vigorous attack on the supineness of 
 English business men in regard to the adoption of scientific 
 methods and scientific assistance. 
 
 In a letter to Nature on " Indigo and Sugar," Dr F. Molwo 
 Perkin also pertinently asks, in reference to the above-quoted 
 figures of the staff at the Badische works, if there "are 148 
 scientific chemists employed by manufacturers in the whole of 
 the United Kingdom ? " 
 
 The present crisis in the indigo industry may possibly benefit 
 others indirectly by inducing them to take advantage, more fully 
 than has been the case in the past, of scientific, and therefore 
 rational and economical, methods of manufacture. 
 
XIII. : 1902 
 
 APPLIED CHEMISTRY, ENGLISH 
 AND FOREIGN 
 
 BY SIR J. DEWAR, M.A., LL.D., D.Sc., F.R.S. 
 (Abstract from Presidential Address, British Association, Belfast, 1902) 
 
 THE diplomatic and consular reports published from time to 
 time by the Foreign Office are usually too belated to be of much 
 use to business men, but they sometimes contain information 
 concerning what is done in foreign countries which affords food 
 for reflection. One of these reports, issued a year ago, gives a 
 very good account of the German arrangements and provisions 
 for scientific training, and of the enormous commercial demand 
 for the services of men who have passed successfully through the 
 universities and Technical High Schools, as well as of the wealth 
 that has accrued to Germany through the systematic application 
 of scientific proficiency to the ordinary business of life. 
 
 Taking these points in their order, I have thought it a matter 
 of great interest to obtain a comparative view of chemical equip- 
 ment in this country and in Germany, and I am indebted to 
 Professor Henderson of Glasgow, who last year became the 
 secretary of a committee of this Association of which Professor 
 Armstrong is chairman, for statistics referring to this country, 
 which enable a comparison to be broadly made. The author of 
 the consular report estimates that in 1901 there were 4500 
 trained chemists employed in German works, the number having 
 risen to this point from 1700 employed twenty-five years earlier. 
 It is difficult to give perfectly accurate figures for this country, 
 but a liberal estimate places the number of works chemists at 
 1500, while at the very outside it cannot be put higher than 
 somewhere between 1500 and 2000. In other words, we cannot 
 
 222 
 
APPLIED CHEMISTRY, ENGLISH AND FOREIGN 223 
 
 show in the United Kingdom, notwithstanding the immense 
 range of the chemical industries in which we once stood promi- 
 nent, more than one-third of the professional staff employed in 
 Germany. It may perhaps be thought or hoped that we make 
 up in quality for our defect in quantity, but unfortunately this is 
 not the case. On the contrary, the German chemists are, on the 
 average, as superior in technical training and acquirements as 
 they are numerically. Details are given in the report of the 
 training of 633 chemists employed in German works. Of these, 
 69 per cent, hold the degree of Ph.D., about 10 per cent, hold 
 the diploma of a Technical High School, and about 5 per cent, 
 hold both qualifications. That is to say, 84 per cent, have 
 received a thoroughly systematic and complete chemical training, 
 and 74 per cent, of these add the advantages of a university 
 career. Compare with this the information furnished by 500 
 chemists in British works. Of these only 21 per cent, are 
 graduates, whilst about 10 per cent, hold the diploma of a college. 
 Putting the case as high as we can, and ignoring the more 
 practical and thorough training of the German universities, which 
 give their degrees for work done, and not for questions asked 
 and answered on paper, we have only 3 1 per cent, of systematic- 
 ally trained chemists against 84 per cent, in German works. It 
 ought to be mentioned that about 2 1 per cent, of the 500 are 
 Fellows or Associates of the Institute of Chemistry, whatever 
 that may amount to in practice, but of these a very large number 
 have already been accounted for under the heads of graduates 
 and holders of diplomas. These figures, which I suspect are 
 much too favourable on the British side, unmistakably point to 
 the prevalence among employers in this country of the antiquated 
 adherence to rule of thumb, which is at the root of much of the 
 backwardness we have to deplore. It hardly needs to be pointed 
 out to such an audience as the present that chemists who are 
 neither graduates of a university, nor holders of a diploma from 
 a technical college, may be competent to carry on existing 
 processes according to traditional methods, but are very unlikely 
 to effect substantial improvements, or to invent new and more 
 efficient processes. I am very far from denying that here and 
 there an individual may be found whose exceptional ability 
 enables him to triumph over all defects of training. But in all 
 educational matters it is the average man whom we have to 
 consider, and the average ability which we have to develop. 
 
224 THE BRITISH COAL-TAR INDUSTRY 
 
 Now, to take the second point the actual money value of the 
 industries carried on in Germany by an army of workers both 
 quantitatively and qualitatively so superior to our own. The 
 consular report estimates the whole value of German chemical 
 industries at not less than fifty millions sterling per annum. 
 These industries have sprung up within the last seventy years, and 
 have received enormous expansion during the last thirty. They 
 are, moreover, very largely founded upon basic discoveries made 
 by English chemists, but never properly appreciated or scientific- 
 ally developed in the land of their birth. I will place before you 
 some figures showing the growth of a single firm engaged in a 
 single one of these industries the utilisation of coal tar for the 
 production of drugs, perfumes, and colouring matters of every 
 conceivable shade. The firm of Friedrich Bayer & Co. employed, 
 in 1875, 119 workmen. The number has more than doubled 
 itself every five years, and in May of this year that firm employed 
 5000 workmen, 160 chemists, 260 engineers and mechanics, and 
 680 clerks. For many years past it has regularly paid 18 per 
 cent, on the ordinary shares, which this year has risen to 20 per 
 cent. ; and in addition, in common with other and even larger 
 concerns in the same industry, has paid out of profits for immense 
 extensions usually charged to capital account. There is one of 
 these factories, the works and plant of which stand in the books 
 at ; i, 500,000, while the money actually sunk in them approaches 
 to 5,000,000. In other words, the practical monopoly enjoyed 
 by the German manufacturers enables them to exact huge profits 
 from the rest of the world, and to establish a position which, 
 financially as well as scientifically, is almost unassailable. I must 
 repeat that the fundamental discoveries upon which this gigantic 
 industry is built were made in this country, and were practically 
 developed to a certain extent by their authors. But in spite of 
 the abundance and cheapness of the raw material, and in spite of 
 the evidence that it could be most remuneratively worked up, 
 these men founded no school and had practically no successors. 
 The colours they made were driven out of the field by newer and 
 better colours made from their stuff by the development of their 
 ideas, but these improved colours were made in Germany and 
 not in England. Now, what is the explanation of this extra- 
 ordinary and disastrous phenomenon ? I give it in a word want 
 of education. We had the material in abundance when other 
 nations had comparatively little. We had the capital, and we 
 
APPLIED CHEMISTRY, ENGLISH AND FOREIGN 225 
 
 had the brains, for we originated the whole thing. But we did 
 not possess the diffused education without which the ideas of 
 men of genius cannot fructify beyond the limited scope of an 
 individual. I am aware that our patent laws are sometimes held 
 responsible. Well, they are a contributory cause ; but it must 
 be remembered that other nations with patent laws as protective 
 as could be desired have not developed the colour industry. 
 The patent laws have only contributed in a secondary degree, 
 and if the patent laws have been bad the reason for their badness 
 is again want of education. Make them as bad as you choose, 
 and you only prove that the men who made them, and the public 
 whom these men try to please, were misled by theories instead 
 of being conversant with fact and logic. But the root of the 
 mischief is not in the patent laws or in any legislation whatever. 
 It is in the want of education among our so-called educated 
 classes, and secondarily among the workmen on whom these 
 depend. It is in the abundance of men of ordinary plodding 
 ability, thoroughly trained and methodically directed, that 
 Germany at present has so commanding an advantage. It is the 
 failure of our schools to turn out, and of our manufacturers to 
 demand, men of this kind, which explains our loss of some 
 valuable industries and our precarious hold upon others. Let 
 no one imagine for a moment that this deficiency can be remedied 
 by any amount of that technical training which is now the 
 fashionable nostrum. It is an excellent thing, no doubt, but it 
 must rest upon a foundation of general training. Mental habits 
 are formed for good or evil long before men go to the technical 
 schools. We have to begin at the beginning : we have to train 
 the population from the first to think correctly and logically, to 
 deal at first hand with facts, and to evolve, each one for himself, 
 the solution of a problem put before him, instead of learning by 
 rote the solution given by somebody else. There are plenty of 
 chemists turned out, even by our universities, who would be of 
 no use to Bayer & Co. They are chock-full of formulae, they 
 can recite theories, and they know text-books by heart ; but put 
 them to solve a new problem, freshly arisen in the laboratory, 
 and you will find that their learning is all dead. It has not 
 become a vital part of their mental equipment, and they are 
 floored by the first emergence of the unexpected. The men who 
 escape this mental barrenness are men who were somehow or 
 other taught to think long before they went to the university. 
 
 15 
 
226 THE BRITISH COAL-TAR INDUSTRY 
 
 To my mind, the really appalling thing is not that the Germans 
 have seized this or the other industry, or even that they may 
 have seized upon a dozen industries. It is that the German 
 population has reached a point of general training and specialised 
 equipment which it will take us two generations of hard and 
 intelligently directed educational work to attain. It is that 
 Germany possesses a national weapon of precision which must 
 give her an enormous initial advantage in any and every contest 
 depending upon disciplined and methodised intellect. 
 
XIV.: 1903 
 
 THE RELATION BETWEEN SCIENTIFIC 
 RESEARCH AND CHEMICAL INDUSTRY 
 
 BY PROFESSOR R. MELDOLA, F.R.S. 
 
 (Lecture delivered at the Oxford Summer Meeting, August 1903) 
 
 THIS lecture deals in a general manner with the interdependence of 
 science and industry, using as illustrations the manufacture of optical 
 glass, fertilisers, the fermentation industries, and the coal-tar colour 
 industry. The fundamental necessity of both pure and technical 
 research is insisted upon. 
 
 227 
 
XV.: 1905 
 
 THE HISTORY OF THE COAL-TAR COLOUR 
 INDUSTRY BETWEEN 1870 AND 1885 
 
 BY PROFESSOR R. MELDOLA, F.R.S. 
 
 (Abstract of a Memorandum which accompanies the Report of the 
 Committee on Industrial Alcohol : Journal of the Society of Dyers 
 and Colourists^ 1905, p. 175) 
 
 THE chief dyes made in England during the period 1870-1885 
 were magenta, aniline blue, its sulpho acids and by-products, 
 Hofmann violets, iodine green, Bismarck brown, aniline yellow, 
 indulines, phosphine, safranine, chrysoidine, naphthol orange 
 and other azo dyes, picric acid, Manchester yellow, alizarin. 
 During the same period the dyes made abroad, in addition to the 
 above colouring matters, were methyl violet, crystal violet, etc. ; 
 methylene blue, acid magenta, malachite green, brilliant green, 
 Victoria blue, night blue, auramine, etc. ; monazo colours from 
 homologues of aniline and sulpho acids of naphthols, disazo 
 colours of various kinds, and especially the direct cotton dyes ; 
 oxazines, such as gallocyanine, etc. ; phthalems. The decline in 
 our coal-tar colour industry began about the year 1880. In 1886 
 about 90 per cent, of the dyes used in England were of foreign 
 manufacture. The statement that the industry has been driven 
 out of the country for want of duty-free spirit is quite erroneous, 
 because it can be shown that during the earlier years the question 
 of the price of alcohol was quite a subordinate one. Our supre- 
 macy had, in fact, been lost long before the price of alcohol, as 
 compared with the prices of the finished products, had become a 
 matter of any great importance. The cost of alcohol as a factor 
 in determining the cost price of dyestuffs could be left out of 
 consideration altogether, but the further back we go into the 
 history of the industry, the less important does the price of 
 
 228 
 
INFLUENCE OF SPIRIT DUTY 229 
 
 alcohol become. It is perhaps fair to say that during the period 
 anterior to 1870 it was practically negligible, and during the 
 period 1870-1880 it was of quite minor consideration certainly 
 the relative cost of alcohol at that period does not warrant the 
 belief that our loss of the manufacture had anything to do with 
 the spirit duties. 
 
 Beginning with the home list. Hofmann's violet and iodine 
 green are the only dyes into the composition of which the alcohol 
 radical (methyl) enters. They were made from rosaniline and 
 methyl iodide, which was then made from wood naphtha, and 
 was not taxed. None of the other dyes on the list required 
 alcohol in any quantity excepting aniline blue, in which case it 
 was used as a solvent. Methylated spirit was used, and after- 
 wards recovered with little loss. The conclusion seems to be 
 inevitable that the spirit duty had nothing whatever to do with 
 the matter. Hofmann's violet is now extinct, but aniline blue 
 and its derivatives are still important products, but we have lost 
 our supremacy, and by far the largest proportion of these dye- 
 stuffs now on the market is of foreign manufacture. We lost 
 ground, therefore, in a branch of manufacture which was supreme 
 in this country, and for which, although alcohols were required, 
 no excuse for our decadence could possibly have been based on 
 the plea that the spirit duties were to blame. Alizarin, one of 
 the most important products, was at one time manufactured by 
 Perkin's firm and their successors, and afterwards by the British 
 Alizarin Company. Although the raw material anthracene is 
 produced in large quantities in this country, the manufacture of 
 alizarin here became practically extinct for many years, although 
 it is now being restored. Whatever may have been the causes 
 of our temporary decadence in this case, the success of our com- 
 petitors cannot possibly be attributed to their command of duty- 
 free spirit, because alcohol is not used. 
 
 The proximate causes of our decadence, so far as these are 
 concerned with the alcohol question, may be said to be the dis- 
 covery of new colouring matters and processes by foreign chemists, 
 and the improvement of the processes for manufacturing the pro- 
 ducts already in existence. The want of duty-free spirit in regard 
 to these improved processes cannot have been great during the 
 period 1 870-1 885. The introduction of new dyestuffs is, however, 
 of fundamental importance. Coming to the foreign list, with the 
 exception of the oxazines all these compounds were discovered by 
 
2 3 o THE BRITISH COAL-TAR INDUSTRY 
 
 foreign chemists. The author discovered the first member of the 
 oxazines in 1879, ^ ut ^ was not manufactured here until many 
 years later, and then not in the factory where it was discovered. 
 The manufacture was at once taken up in Germany. In this case, 
 although one of the raw materials contains the radical of methyl 
 alcohol, the duty upon pure wood spirit had nothing to do with 
 the transference of the manufacture of this colouring matter. 
 
 The introduction in 1866 of methyl violet (Poirrier) first 
 created a demand for dimethylaniline which contains the radical 
 methyl. Dimethylaniline was also necessary for methylene blue 
 (1876), malachite green (1878), crystal violet, Victoria blue, and 
 auramine (1883). Diethylaniline was necessary for brilliant 
 green (1879) and night blue (1883). At the time, therefore, 
 when the decline of the industry had seriously set in, with the 
 exception of methyl violet, none of the dyestufFs on the foreign 
 list were made in this country, and the dimethyl and diethyl- 
 anilines were being manufactured abroad for the manufacture of 
 dyes discovered by foreign chemists. The effect of these newer 
 colouring matters upon the dyestufFs being made here at the time 
 of their introduction is evidently connected with the loss of our 
 supremacy. Hofmann's violet was gradually replaced by methyl 
 violet, and iodine green, which, however, was only produced in 
 limited quantity, was rapidly extinguished by the malachite green 
 group. Victoria blue and methylene blue did not seriously inter- 
 fere with our aniline blue group, as they fulfilled a different 
 function in the tinctorial industry. In 1880, therefore, the only 
 one of our dyestuffs directly affected by the introduction of di- 
 methylaniline was Hofmann's violet. To what extent did the 
 command of duty-free alcohol give our competitors an advantage 
 in the manufacture of such dyestuffs as methyl violet, methylene 
 blue, and malachite green ? They were all foreign patents. When 
 methyl violet was made here the patent had lapsed, the dimethyl- 
 aniline being imported from abroad, as its manufacture was not 
 taken up here down to 1885, in spite of Government concessions 
 in regard to duty-free alcohol when the point was first raised in 
 1880. Dimethylaniline can be made by heating aniline hydro- 
 chloride with pure methyl alcohol in autoclaves which were used 
 on the Continent at this time, but not here. It can also be made 
 by the action of methyl chloride, obtained in 1878 from tri- 
 methylamine, a beet sugar by-product, upon aniline. It there- 
 fore could not be produced cheaply in England. At that period 
 
INFLUENCE OF SPIRIT DUTY 231 
 
 all the coal-tar colours were commanding such prices that the cost 
 of the alcohol was insignificant as compared with the margin of 
 profit. Methyl violet displaced Hofmann's violet because it is 
 made directly from its raw material, whereas Hofmann's violet 
 has to go through several reactions, including the use of methyl- 
 iodide. 
 
 With the exception of methyl violet, every one of the new 
 products necessitated the manufacture of some new raw material, 
 such as benzoic aldehyde for malachite green, phenylnaphthyl- 
 amine for Victoria blue, tolylnaphthylamine for night blue, etc. 
 None of these raw materials required alcohol for their production. 
 The difference in cost between the dyestuffs made from duty-paid 
 or duty-free alcohol, as compared with the margin of profit, was 
 quite insignificant. During the period dealt with our industry 
 was seriously affected by the inventive activity of the foreign 
 manufacturers, but its decline cannot be attributed to their having 
 the use of duty-free alcohol. 
 
 The conditions have changed since 1885. Prices were falling 
 from 1880, and the margin of profit becoming smaller. The 
 difference in the cost of manufacture due to the use of duty-free 
 spirit would now bear a very much larger ratio to the margin of 
 profit, and whereas this difference was formerly for all practical 
 purposes a negligible quantity, it may now have become a serious 
 factor. For this reason the author's opinion is that it is desirable 
 that our chemical manufacturers should be placed upon the same 
 footing as their foreign competitors so far as concerns the use of 
 duty-free alcohol. 
 
XVI.: 1906 
 
 NOTE ON THE PERKIN JUBILEE 
 
 To mark the fiftieth anniversary of the discovery of the first 
 coal-tar dyestuff and as a personal tribute to Sir William Perkin, 
 an international meeting was held at the Royal Institution, 
 London, on Thursday, 26th July 1906. 
 
 Special representatives were present from Germany, Austria, 
 France, Belgium, Holland, Switzerland, Italy, Denmark, Russia, 
 and the United States, in addition to a very representative 
 gathering of British chemists, and a large number of addresses 
 were presented to Sir William Perkin from British and Foreign 
 chemical and other societies, universities, etc. 
 
 A further celebration was held in the autumn of the same year 
 when Sir William Perkin visited the United States. 
 
 Many interesting references dealing with the history and 
 development of the coal-tar colour industry will be found in the 
 speeches delivered and addresses presented on the occasion of 
 the London and New York celebrations, but they cannot usefully 
 be summarised here. 
 
 A full report of the whole of the proceedings was published 
 in book form by the Perkin Memorial Committee and issued by 
 The Times Office, London. 
 
 232 
 
XVII. : I 9 o8 
 PERKIN OBITUARY NOTICE 
 
 BY PROFESSOR R. MELDOLA, F.R.S. 
 
 (Journal of the Chemical Society^ 1908, p. 2214) 
 
 THIS lecture constitutes the Obituary Notice of Sir William Perkin 
 contributed to the Chemical Society. It gives a complete review of 
 Perkin s life and work, but the points of especial interest from the 
 point of view of the present work are largely covered by the following 
 papers : 
 
 Perkin : " The Colouring Matters produced from Coal-tar" 
 
 t; 75- 
 Perkin : " The Origin of the Coal-tar Colour Industry" 
 
 p. 141. 
 
 Meldola : " The Founding of the Coal-tar Colour Industry" 
 P- 234. 
 
 2 33 
 
XVIII. : I 9 o8 
 
 THE FOUNDING OF THE COAL-TAR 
 COLOUR INDUSTRY 
 
 BY PROFESSOR R. MELDOLA, F.R.S. 
 
 (Presidential Address to the Society of Dyers and Colourists, 1908 : 
 Journal of the Society of Dyers and Colour ists^ 1908, p. 95) 
 
 THE late President of the Society, Sir William Henry Perkin, 
 passed away on i/j-th July 1907, in the sixty-ninth year of his 
 age, and in the zenith of his fame. It would be superfluous to 
 retell here the story of the discovery of mauve, or the influence 
 of that discovery upon the tinctorial industries. The great inter- 
 national gathering of 1906, which will still be fresh in your 
 memories, furnished ample opportunity for reviewing the life- 
 work of the man whom the nations had assembled to honour, 
 and he himself gave a very full account of his connection with 
 the industry. This is all recorded in the official report of the 
 jubilee meeting published by the Memorial Committee. Some 
 interesting reminiscences were also given by Sir Robert Pullar 
 and others at last year's annual dinner, at which Sir William 
 Perkin presided, and of which a full report was published in the 
 April number of the Journal. I have, moreover, written an 
 obituary notice of him for the Royal Society, and in this I have 
 endeavoured to do justice to his scientific work and personal 
 character. It cannot but be a source of the greatest satisfaction 
 to us all the one mitigating circumstance that lightens our 
 sorrow at his loss that he fell from our ranks not unrecognised, 
 as is the fate of so many of our scientific pioneers in this country, 
 but laden with freshly bestowed honours, and with the full 
 knowledge that his labours had won lasting gratitude in the two 
 great spheres of human activity, Science and Industry. Further- 
 
 234 
 
THE FOUNDING OF THE INDUSTRY 235 
 
 more, it cannot but be a gratifying memory to us that our 
 Society throughout its future history will be able to point to the 
 name of Perkin on the roll of its past Presidents. He died in 
 our service, and one of his last acts in connection with this 
 Society was to accompany the deputation to the Dyers' Company 
 in order to plead with that worshipful body for assistance in 
 founding prizes to be awarded by our Society for the solution of 
 technical problems connected with the industry. 
 
 On the present occasion our annual gathering, saddened by 
 the loss of our late President, will be made memorable by its 
 marking the first award of the Perkin medal, founded in 1906 
 in celebration of the jubilee of the discovery and manufacture 
 of the first coal-tar colouring matter. No more fitting tribute 
 to the memory of my distinguished predecessor could be paid 
 than that his successor in this chair should endeavour to enable 
 you to realise the full measure of our indebtedness to him. I 
 propose therefore to invite you to take with me a retrospective 
 glance into the conditions, scientific and industrial, antecedent to 
 that accidental discovery of 1856, which marked the beginning 
 of the modern revolution in all tinctorial methods. Let us con- 
 sider, in the first place, the state of affairs with respect to the raw 
 materials required for the manufacture of mauve. These were 
 benzene, nitrobenzene, and aniline. 
 
 Benzene, as you are aware, was discovered by Michael Faraday, 
 in 1825, as a component of the liquid obtained by the compression 
 of oil-gas. Twenty years later Hofmann found this hydrocarbon 
 in coal-tar, and proved its presence by preparing from it nitro- 
 benzene and aniline, the latter being identified by the usual tests. 
 The occurrence of benzene in coal-tar was thus known in 1 845, 
 and in 1 848 one of Hofmann's brilliant young students at the 
 Royal College of Chemistry, Charles Blachford Mansfield, at the 
 instigation of his illustrious master, undertook a systematic study 
 of coal-tar, with a view to the isolation and identification more 
 especially of the " neutral liquid oils," of which he tells us in his 
 paper published by the Chemical Society in 1 849 we had at that 
 time " no precise information." When Mansfield took up this 
 work a few definite compounds were known to exist in this tar, 
 notably naphthalene, which had been isolated by Garden in 1820, 
 and certain acid and basic substances, such as phenol (carbolic 
 acid), aniline (kyanol), quinoline (leucol or leucoline), and pyrole, 
 all of which had been isolated by Runge in 1834. Anthracene, 
 
236 THE BRITISH COAL-TAR INDUSTRY 
 
 under the name of " paranaphthaline," was isolated by Dumas 
 and Laurent in 1833, although it is now known that their original 
 analysis, which assigned to this hydrocarbon 15 atoms of carbon, 
 was erroneous. Chrysene and pyrene had also been indicated, 
 but only superficially studied by Laurent in 1837. To the basic 
 constituents picoline was added in 1846 by Anderson. 
 
 Such was the state of knowledge when Hofmann set Mansfield 
 to work upon the coal-tar hydrocarbons. The paper embodying 
 his results is entitled " Researches on Coal Tar, Part I.," x and 
 now, nearly sixty years after its publication, it can still be read with 
 interest and profit. Its contents have become historic in con- 
 nection with the colour industry, and must rank with Runge's 
 celebrated papers of i834 2 among the most important con- 
 tributions to tar chemistry that preceded the foundation of that 
 industry. 
 
 Even at the time of Mansfield's work no coal-tar hydrocarbon 
 had been utilised as a source of other chemical compounds, 
 tinctorial or otherwise, and he himself, in describing the practical 
 applications of benzene, refers only to its use as a solvent or an 
 illuminant. Perkin's discovery thus created a demand for this 
 hydrocarbon as a raw material in a new industry on a scale never 
 before contemplated. Mansfield's experiments had prepared 
 the way, but there had been no demand for benzene, and the 
 tar distillers could not at first supply it in quantity or in a 
 sufficient state of purity. It is of interest to know that the 
 first supply of this material used by Perkin came from the Scotch 
 tar distillery of Messrs Miller & Co., of Glasgow. 
 
 Then came the difficulties connected with the nitration and 
 the reduction of the nitrobenzene to aniline. Here again 
 Mansfield had played the part of a pioneer, but his process 
 was impracticable on the scale now required. Moreover, it 
 was too costly, for it must be borne in mind that the new dye 
 had to compete with the existing vegetable colouring matters, 
 and on I2th June 1856, Messrs Pullar, of Perth, who had 
 been testing the dyeing properties of mauve, had reported to 
 
 1 Chem. Soc. Quart. Jour., 1849, vol. i. p. 244. He gave a general 
 account of his work at a Friday evening discourse at the Royal Institution 
 on 2yth April 1849, which was published as a brochure, entitled "Benzole: 
 its Nature and Utility." 
 
 2 Poggendorff's A nnalen, vol. xxxi. pp. 65 and 513; vol. xxxii. pp. 308 
 and 328. 
 
THE FOUNDING OF THE INDUSTRY 237 
 
 Perkin that the discovery was a valuable one provided it did not 
 " make the goods too expensive." It is needless to say that 
 nitric acid of the strength used by Mansfield would have been 
 a very costly material in 1856. In fact, nitric acid of sufficient 
 strength to nitrate benzene could not be obtained in quantity 
 at that period, and Perkin had to devise apparatus for nitrating 
 with a mixture of sulphuric acid and sodium nitrate. His 
 resourcefulness is well revealed by this passage quoted from his 
 Hofmann Memorial Lecture in 1876 : "At this time neither 
 I nor my friends had seen the inside of a chemical works, and 
 whatever knowledge I had was obtained from books. This, 
 however, was not so serious a drawback as at first it might 
 appear to be, as the kind of apparatus required, and the character 
 of the operations to be performed, were so entirely different from 
 any in use that there was but little to copy from. 
 
 " In commencing this manufacture it was absolutely neces- 
 sary to proceed tentatively, as most of the operations required 
 new kinds of apparatus to be devised and tried before more 
 could be ordered to carry out the work on any scale " (see 
 p. 153, ante). 
 
 After the manufacture of mauve had been started the 
 demand for the new dyestufF increased to such an extent that 
 the resources of the Greenford factory were taxed to their 
 utmost, and the assistance of another firm had to be called in 
 for supplying raw materials. That firm was Simpson, Maule & 
 Nicholson, whose factory was at Locksfields, in the south of 
 London. The Nicholson of the firm was that pupil of Hofmann's 
 already referred to as having been a co-worker with Mansfield, 
 and, under his energetic management, they not only supplied 
 the firm of Perkin & Sons with some of the raw materials 
 required, but later they also entered the colour industry, and 
 in 1865 established the Atlas Works at Hackney Wick, the 
 firm being transferred in 1868 to Messrs Brooke, Simpson & 
 Spiller. Mr William Spiller, formerly of this latter firm, has 
 told me that he well remembers the early stages in the 
 manufacture of nitrobenzene by their predecessors at Locksfields, 
 where he was then working in association with the late 
 Mr E. C. Nicholson. The nitration was carried out in large 
 glass " boltheads " arranged in series, as they had not then 
 discovered that cast-iron vessels could be used. The scale of 
 working was quite small as compared with the modern output 
 
238 THE BRITISH COAL-TAR INDUSTRY 
 
 from a large nitrating still, and they experienced the difficulty 
 referred to by Perkin of obtaining a supply of pure benzene. 
 The operation also was somewhat capricious, owing to the want 
 of uniformity in the quality of the commercial " benzole," 
 and to the absence of mechanical stirring. The cheapening 
 of the process by the introduction of cast-iron stills with 
 mechanical stirring gear did not take place until some time after 
 the manufacture of mauve had been commenced in 1857. The 
 plant in use was described and figured by Perkin in his Cantor 
 Lectures, delivered before the Society of Arts in 1868, and has 
 since been refigured in many works on technology, as it is 
 practically the same in principle as that now generally in use. 1 
 
 The next step, the reduction to aniline, had also to be 
 worked out on the manufacturing scale. The laboratory method 
 then generally in use was Zinin's, viz. sulphuretted hydrogen 
 in presence of ammonia, a process obviously impracticable on 
 the large scale. The use of metals, such as tin or zinc, in 
 combination with acids, would have been both costly and 
 unmanageable. Fortunately, however, Bechamp in 1854 had 
 found that iron and acetic acid could be used for reducing 
 nitro compounds, and Perkin, who had been familiarised with 
 this process in Hofmann's laboratory, applied it successfully for 
 the manufacture of aniline. 2 That this was a task of considerable 
 difficulty can be readily understood by those who are familiar 
 with the violence of such " reducing " processes, unless properly 
 controlled. It is, in fact, known that at first serious attempts 
 were made to extract the minute quantity of aniline contained 
 in the coal-tar oils directly by acid washing a process which, 
 it is needless to say, had soon to be abandoned on account of 
 its cost and the impure state of the product. In the manufacture 
 of aniline from nitrobenzene the firm of Simpson, Maule & 
 Nicholson also co-operated with Perkin & Sons, and Mr 
 William Spiller has given me a graphic description of their 
 
 1 A workman, James Underwood, in the employment of Simpson, Maule 
 & Nicholson, at Locksfields, during the early years of the colour industry, 
 also remembers this manufacture of nitrobenzene in boltheads and the 
 development to cast-iron stills. This last improvement is generally attri- 
 buted to E. C. Nicholson. A figure of the earliest form of (horizontal) 
 still was given by Perkin in his Cantor Lectures above referred to. 
 
 2 " Had it not been for this discovery the coal-tar colour industry could 
 not have been started." W. H. Perkin, Hofmann Memorial Lecture (see 
 p. 153, ante). 
 
THE FOUNDING OF THE INDUSTRY 239 
 
 early work at Locksfields when starting this branch of the 
 industry. The reduction was carried out in iron vessels with 
 removable still-heads, the vessel being at first uncovered, and 
 the materials, nitrobenzene, iron turnings, and acetic acid, simply 
 stirred up by a rod until the reaction showed signs of starting. 
 The still-head was then immediately clapped on, and a workman 
 mounted guard with water-hose ready to play over the still if 
 the contents gave signs of boiling too violently. The cost of 
 the acetic acid was a considerable item at that time, and they 
 had to make their own acid by heating sodium acetate with 
 sulphuric acid. It was soon found that hydrochloric acid could 
 be used instead of acetic acid, and the introduction of stills 
 with mechanical stirrers put this branch of the manufacture on 
 a sure basis. It is perhaps hardly necessary to point out that 
 the "aniline" of that period was a mixture of homologues, and 
 very impure from the modern point of view. 
 
 And so the manufacture of the first of the "synthetic 
 dyestuffs " was started at Greenford Green towards the end of 
 the year 1857, and the genius of the founder had ample scope 
 for exercise. Let it be borne in mind that the raw product 
 obtained by oxidising crude aniline with sulphuric acid and 
 potassium dichromate was what would now be called a " resinous 
 mess." Processes for its purification had to be devised, and 
 here again the resourcefulness of Perkin becomes manifest. 
 With that true scientific spirit which dominated all his work 
 the investigation of his products and processes was always kept 
 going. At first the crude product was collected on filters and 
 washed with water to remove excess of aniline sulphate, then 
 dried and powdered, and extracted with coal-tar " naphtha " 
 until free from resinous impurities, then dried again and 
 extracted with methylated spirit, and the filtered solution distilled 
 until the dyestufF separated out. This method of purification 
 was afterwards improved and cheapened by the omission of the 
 naphtha treatment, as it was found that diluted methylated 
 spirit extracted the colouring matter directly, and left the resin 
 undissolved. The process was finally simplified by boiling out 
 the colouring matter with water alone, and precipitating with an 
 alkali so as to obtain the free base, which was then converted 
 into acetate for use by the dyers. 
 
 The discovery and manufacture of mauve, with its train of 
 consequences, must be regarded as constituting but a portion of 
 
2 4 o THE BRITISH COAL-TAR INDUSTRY 
 
 Perkin's claim to our gratitude. In starting upon this work he 
 had, against the advice of his illustrious master, Hofmann, 
 broken away from the path of pure science and entered a field 
 in which he was a novice. His whole future was bound up with 
 the success of the undertaking, for his father had placed nearly 
 his entire capital in the venture in order to establish the factory 
 at Greenford Green. There was evidently something more to 
 be done besides placing the new dyestuff on the market. The 
 dyers and printers had to be convinced of its merits and taught 
 how to use it. This task, by no means a light one, had also to 
 be undertaken by Perkin, who, up to that time, had never been 
 brought into contact with the tinctorial industries. It has fre- 
 quently been mentioned that Messrs Pullar, of Perth, were the 
 first to give encouragement to the young inventor so far as 
 concerned the dyeing properties of mauve. At their instigation 
 it was tried for silk dyeing by Thomas Keith, silk dyer, of 
 Bethnal Green, London, and he also reported favourably. But, 
 as is generally the case with new departures, the step from the 
 experimental to the practical scale was not made without en- 
 countering difficulties. It was found that on the large scale 
 the dye " took on " unevenly, and caused a patchy appearance, 
 so that a restraining material had to be added to the bath. The 
 use of the soap bath for silk dyeing was the outcome of Perkin's 
 association with a practical dyer, and Keith's dyehouse was the 
 first in which mauve was used on the industrial scale. 
 
 Then with respect to wool and cotton dyeing, the same 
 pioneering work had to be done. Perkin has told us that he 
 and Mr (now Sir) Robert Pullar had independently discovered 
 the use of tannin and a metallic oxide as a mordant for cotton 
 dyeing, and, in conjunction with Alexander Schultz, he had 
 introduced the " insoluble arsenite of alumina " as a mordant. 
 The calico printers in this country did not at first take kindly to 
 the new colouring matter, and Perkin has often told me that 
 the impetus to this most important application of his discovery 
 came from France. It appears that, owing to some technical 
 oversight, the French patent was ineffective, and the French 
 manufacturers accordingly began making the new dyestuff them- 
 selves. It was in France, in fact, that the term " mauve " was 
 given. With the well-known skill of the French calico printers 
 beautiful designs in mauve were produced and sent over to this 
 country, and this was more effective than any other cause in 
 
THE FOUNDING OF THE INDUSTRY 241 
 
 hastening the use of the dye for this purpose over here. Had 
 it not been for this stimulus the success of the new factory would 
 have been doubtful, for Messrs Pullar had reported to Perkin that, 
 in their opinion, unless the new dye could be used by the printers 
 it would be questionable whether " it would be wise to erect works 
 for the quantity dyers alone will require." l In summing up this 
 part of his experience Perkin stated in 1896 : 
 
 " Before the aniline purple could be introduced for dyeing 
 woollen and mixed fabrics, some weeks were also spent at 
 Bradford in rinding out suitable methods of applying it. 
 
 " Thus it will be seen that, in the case of this new colouring 
 matter, not only had the difficulties incident to its manufacture 
 to be grappled with, and the prejudices of the consumer over- 
 come, but, owing to the fact that it belonged to a new class 
 of dyestuffs, a large amount of time had to be devoted to the 
 study of its applications to dyeing, calico printing, etc. It was, 
 in fact, all pioneering work clearing the road, as it were, for 
 the introduction of all colouring matters which followed, all 
 the processes worked out for dyeing silk, cotton, and wool, 
 and also for calico printing, afterwards proving suitable for 
 magenta, Hofmann violet, etc." (Hofmann Memorial Lecture, 
 loc. cif., p. 609.) 
 
 It will be remembered that at our last anniversary dinner, 
 presided over by Perkin, Sir Robert Pullar gave us some of 
 his early reminiscences concerning the attitude of the Scotch 
 calico printers towards the new colouring matter. 
 
 The success of the new industry had for its natural con- 
 sequence the creation of a host of imitators. All kinds of 
 oxidising agents were tried upon aniline and made the subjects 
 of rival patents. The departure from the original patent was 
 in some cases so slight that it is questionable whether in modern 
 patent legislation the inventor's claim would not be dismissed as 
 a " colourable imitation." Tabourin and Franc Bros, claimed 
 aniline hydrochloride instead of sulphate ; Beale and Kirkham 
 in England, as well as Scheurer-Kestner, Depouilly and Lauth, 
 Coblentz, and C. Phillips in France, claimed bleaching powder ; 
 
 1 " I distinctly remember, the first time I induced a calico printer to 
 make trials of this colour, that the only report I obtained was that it was too 
 dear, and it was not until nearly two years afterwards, when French printers 
 put aniline purple into their patterns, that it began to interest English 
 printers." Perkin's Cantor Lectures, Society of Arts (see p. 15, ante). 
 
 16 
 
242 THE BRITISH COAL-TAR INDUSTRY 
 
 Smith claimed chlorine water, Greville Williams potassium per- 
 manganate, Kay manganese dioxide, David Price (attached to 
 the firm of Simpson, Maule & Nicholson) claimed lead 
 peroxide, Dale and Caro cupric chloride, Stark and Guyot 
 red prussiate of potash, and so forth. It is needless to point 
 out that many of the products obtained by these inventors 
 could not have been Perkin's mauve at all, and, as a matter 
 of fact, not one of these rival processes was enabled to com- 
 pete successfully with the original " bichromate " method. The 
 yield was too small, or the colour too difficult to purify, or 
 the oxidising agent too expensive, although at that time the 
 bichromate cost from icd. to nd. per pound. The only one 
 of these processes which gave a good result was Dale and 
 Caro's, but even this could not be worked so economically as 
 the original process. 
 
 The introduction of mauve by the founder of and pioneer 
 in this new development in manufacturing chemistry soon led, 
 as you are all aware, to the further discovery of coal-tar colouring 
 matters and to the establishment of other factories. My present 
 theme centres round Perkin's work in this field, and I do not 
 propose to enlarge upon the discoveries of others excepting in 
 so far as they influenced the life of our late President. For 
 about a decade the manufacturing operations at Greenford were 
 carried on successfully, and without any fresh discovery of very 
 great importance, although Perkin's activity in the field of pure 
 scientific investigation never ceased. Magenta was first made 
 industrially by Verguin, in France, in 1859, and the firm of 
 Simpson, Maule & Nicholson soon began to manufacture this 
 on the large scale by the arsenic acid process as well as other 
 well-known colouring matters. Such was the development of 
 the industry that in 1862, the year of the International Exhibition 
 in London, Hofmann gave a Friday evening discourse at the 
 Royal Institution, 1 from which it appears that the definite com- 
 pounds which had been isolated from coal-tar, and which in 
 Mansfield's lists of 1 848 consisted of thirteen, had then risen to 
 about forty. It was for that Exhibition that Messrs Simpson, 
 Maule & Nicholson prepared a crown of magenta crystals 
 (acetate), which Hofmann exhibited during his lecture, the title 
 of which was " Mauve and Magenta." The selling price of the 
 new dyes at that time may be gathered from the circumstance 
 1 Chemical News, vol. vi. p. 90. 
 
THE FOUNDING OF THE INDUSTRY 243 
 
 that the purified solid mauve sold for about the same price as 
 platinum, weight for weight, and the vat from which the 
 magenta cc crown " had been crystallised contained a weight of 
 the acetate of that base valued at j8ooo, the crystals adhering 
 to the wire framework of the crown being valued at ^roo. 1 
 
 The discovery and manufacture of magenta was undoubtedly, 
 after the production of mauve, the most important contribution 
 to the industry made during the decade referred to. This dis- 
 covery did not at first affect Perkin's operations ; mauve still 
 held its own, and in 1859 Perkin's brother Thomas, the 
 business man of the establishment, patented on behalf of the 
 firm a process for making magenta by oxidising crude aniline 
 with mercuric nitrate. 2 This was an improvement upon the 
 original stannic chloride process of Verguin, but it was 
 dangerous, capricious, and expensive, and was very soon dis- 
 placed by Medlock's arsenic acid process worked by Simpson, 
 Maule & Nicholson, and also, as the result of a celebrated 
 lawsuit, by Messrs Read Holliday & Sons, of Huddersfield. 
 But although Perkin & Sons never made magenta in any 
 quantity, the introduction of this dyestuff led to new and 
 necessary developments in their factory. About five years after 
 the foundation of the Greenford works, Hofmann, who had 
 then enthusiastically entered the field of colour chemistry, found 
 that magenta when ethylated or methylated gave rise to 
 violet colouring matters, the manufacture of which was at once 
 taken up by Simpson, Maule & Nicholson. 3 Hofmann's violets 
 and certain phenylated rosanilines, discovered about the same 
 time by Girard and De Laire, in France, and made here also by 
 Simpson, Maule & Nicholson, soon began to enter into com- 
 petition with mauve. 
 
 1 Some of the original crystals are now in the possession of Mr William 
 Spiller. A trade catalogue of the firm of Simpson, Maule & Nicholson, 
 placed at my disposal by Dr Cain, shows that in 1866 "pure roseine" was 
 priced at 25. 6d. per oz. 
 
 2 " Das Zinnchlorid wird durch das Quecksilbernitrat ersetzt, mit dem 
 die Fabrikation auch in Deutschland ihre ersten, kraftigen Wurzeln fasst." 
 H. Caro, JBer., 1892, p. 1031. 
 
 3 The manufacture of methyl and ethyl iodide on the large scale was a 
 remarkable achievement at the time. When I entered the Atlas Works, in 
 1877, the Hofmann violets were still being manufactured, and the use of 
 these colouring matters by English dyers continued for more than twenty 
 years after that date. The violet is priced in the 1866 catalogue of Simpson, 
 Maule & Nicholson at 35. per oz. 
 
244 THE BRITISH COAL-TAR INDUSTRY 
 
 It has not, 1 think, been sufficiently dwelt upon by any of the 
 historians of the coal-tar colour industry that Perkin' s pioneering 
 discovery reacted upon itself, for there can be no doubt that the 
 production of aniline on the large scale led to the discovery of 
 processes for the manufacture of magenta, and it was the 
 derivatives of the latter that first began seriously to displace 
 mauve. The discovery by Lauth of colouring matters such as 
 methyl violet, formed by the oxidation of the alkylated anilines 
 and manufactured in France about 1866, brought into the field 
 other competitors with the original mauve. The newer dyes were 
 not so fast as mauve, but they were much more brilliant, and 
 fastness soon gave way to brightness. The practical effect of 
 these later developments made itself felt in the gradual decline 
 in the demand for mauve, the use of which soon became very 
 limited, and finally died out altogether. As a flourishing branch 
 of the colour industry it may be said that mauve did not com- 
 plete ten years of its existence. But Perkin was enabled to 
 keep the Greenford works going successfully in spite of the 
 adverse influence of the new discoveries and the coming into 
 existence of other factories. He introduced in 1864 a very 
 ingenious method for the indirect alkylation of magenta, which 
 enabled their firm to compete with the other violet colouring 
 matters then in the market. This method consisted in heating 
 magenta base with methylated spirit afterwards improved by 
 substituting methyl alcohol and the compound formed from 
 turpentine-oil and bromine in the presence of water. This 
 " brominated turpentine " had long been known to chemists, 
 and had been investigated by Greville Williams, but had never 
 before been used for manufacturing purposes. The dyes thus 
 made were introduced under name of Britannia violet of different 
 shades of blueness, according to the degree of alkylation. It 
 was at first thought that they contained the terpene radicle, 
 although it was afterwards considered that they were of the 
 same type as, if not identical with, the Hofmann violets, so that 
 Perkin had really discovered an indirect method of methylation 
 of a type unknown in chemistry at that time. Perkin's process 
 was very successful, although he was handicapped by having to 
 purchase magenta base, which his firm did not manufacture. 
 But, on the other hand, brominated turpentine was cheaper as an 
 alkylating agent than the methyl iodide used in the manufacture 
 of Hofmann violets. 
 
THE FOUNDING OF THE INDUSTRY 24$ 
 
 I will venture to interpolate here a small experience of my 
 own, because it is connected with this same department of the 
 colour industry, and, although the experiments which I am about 
 to describe were carried out thirty-seven years ago, I have never 
 had such a favourable opportunity for placing them upon record. 
 The violet dyes now known to be alkylated rosanilines were at that 
 time being sold at very high prices, and any new process, i.e. 
 any process which did not infringe existing patents, would have 
 been of very great commercial value. As a youth I had just 
 then entered the colour industry in the service of Messrs 
 Williams, Thomas & Dower, of the Star Chemical Works, 
 Brentford. In 1870 it occurred to me, in view of Perkin's 
 success with brominated turpentine, to try whether the additive 
 compounds of defines with bromine were equally effective, and 
 my first experience in manufacturing chemistry was the produc- 
 tion of ethylene bromide on the large scale. This part of the 
 process was very successfully carried out, and I have a very 
 vivid recollection of the pride with which I displayed ethylene 
 bromide in Winchester quart bottles, the compound being 
 obtained in almost quantitative yield by passing ethylene from 
 alcohol and sulphuric acid through bromine in a special form of 
 apparatus which I devised for this operation. But, alas ! the 
 next part of the process proved a failure. The ethylene bromide 
 did react with the magenta base in presence of methyl alcohol, 
 but the alkylene radicle itself entered the rosaniline molecule 
 there was no transference of radicle as in Perkin's process, and 
 the ethylenerosaniline turned out to be an insoluble resin of no 
 use as a dyestuff. Fuming sulphuric acid might possibly have 
 saved the situation, but this was before the days of "acid 
 magenta," and nobody then knew that such compounds could 
 be sulphonated. 
 
 But to return to the Greenford Green factory. After eleven 
 years' successful working with mauve and certain of its deriva- 
 tives, the Britannia violets, and a few other dyes which are 
 given in the subjoined list, a new impetus suddenly came 
 through the announcement in 1868 that Messrs Graebe and 
 Liebermann, in Germany, had discovered that alizarin, the 
 colouring matter of the madder plant, was a derivative of the 
 coal-tar hydrocarbon] anthracene, and not, as had formerly been 
 supposed, a derivative of naphthalene. The German chemists 
 found also that the compound could be prepared from anthracene, 
 
246 THE BRITISH COAL-TAR INDUSTRY 
 
 and thus was accomplished the first laboratory synthesis of a 
 natural colouring matter. 1 may perhaps be allowed to quote the 
 following passage from my Royal Society obituary notice : 
 
 " This discovery had a great influence upon Perkin's career 
 as an industrial chemist, and may indeed be considered to have 
 marked a new phase of his activity in this field. There was no 
 living worker in this country at that time besides Perkin who 
 so completely combined in himself all the necessary qualifications 
 for taking advantage of such a discovery. Imbued with the 
 spirit of his early ambition to produce natural compounds synthe- 
 tically, with more than a decade's experience as a manufacturer, 
 with the resources of a factory at his disposal, and, not least, 
 with special experience of anthracene as the very substance upon 
 which at Hermann's instigation he commenced his career in 
 research work, it can readily be understood that Graebe and 
 Liebermann's results should have appealed to him with special 
 significance. The first patented process of the German discoverers 
 was confessedly too costly to hold out much hope of successful 
 competition with the madder plant, requiring as it did the use 
 of bromine. Perkin at once realised the importance of cheapen- 
 ing the process by dispensing with the use of bromine, and 
 undertook researches with this object. As a result, the following 
 year (1869) witnessed the introduction of two new methods for 
 the manufacture of artificial alizarin. In one of these processes 
 dichloranthracene was the starting-point, and in the other the 
 sulphonic acid of anthraquinone, the first being of special value 
 in this country owing to the difficulty of obtaining at that time 
 fuming sulphuric acid in large quantities. The second process, 
 which is the one still in use, had quite independently been 
 worked out in Germany by Caro, Graebe, and Liebermann, and 
 patented in England practically simultaneously by these chemists 
 and by Perkin." 1 
 
 The demand for another coal-tar hydrocarbon, anthracene, 
 in large quantities and in a state of purity, necessitated further 
 pioneering work. Supplies of the crude material had to be 
 procured, the tar distillers had to be educated in the production 
 of raw anthracene, and factory methods of purification had to be 
 devised. It is unnecessary for me to remind you that all these 
 requirements were met by the science and skill of Perkin, then 
 
 1 The patents are: Caro, Graebe, and Liebermann, No. 1936, of 25th 
 June 1869, and W. H. Perkin, No. 1948, of 26th June 1869. 
 
THE FOUNDING OF THE INDUSTRY 247 
 
 a young man just turned thirty years of age. The subsequent 
 development of the artificial alizarin industry is too well known 
 to need recital on this occasion. But there is one point in con- 
 nection with Perkin's work in this field which must not be 
 forgotten, and that is the great importance of the dichloranthra- 
 cene process in this country at the outset of the new branch of 
 the coal-tar colour industry. Perkin, in conversation with me, 
 has frequently emphasised this point, and I think it desirable on 
 the present occasion to place once again upon record this chapter 
 in the early history of the alizarin manufacture. 
 
 The two processes discovered by Perkin, and referred to in 
 the preceding extract, were the anthraquinone process and the 
 dichloranthracene process. In the first of these the anthracene 
 is oxidised to anthraquinone, the latter sulphonated by heating 
 with strong sulphuric acid to a high temperature, and the sodium 
 sulphonate converted into alizarin by alkaline fusion. The 
 sulphonation by this process yields a mixture of mono- and 
 di-sulphonic acids, and the final product is therefore a mixture 
 consisting of alizarin, anthrapurpurin, and some flavopurpurin. 
 This was the process first tried on the large scale by Perkin, as 
 well as by the German manufacturers. The second process, 
 which was patented here by Perkin a few months after the 
 patenting of the anthraquinone process, viz. in November 1869, 
 sets out from dichloranthracene, which is sulphonated by ordinary 
 strong sulphuric acid and the product submitted to alkaline fusion 
 as before. Now dichloranthracene sulphonates more readily than 
 anthraquinone, and as the product consists chiefly of a disulphonic 
 acid of anthraquinone, the " artificial alizarin " obtained by this 
 process consists mainly of anthrapurpurin, with some alizarin and 
 flavopurpurin. Alizarin, as you are aware, gives bluer shades of 
 colour than anthrapurpurin, so that although for certain purposes 
 where bright red was required the mixture obtained by Perkin's 
 second process possessed an advantage, for the production of the 
 bluer reds the anthraquinone product had the advantage. Perkin 
 met this difficulty to some extent by devising a method for 
 separating his " alizarin " into " blue shade " and " scarlet shade," 
 but this method was not easy to carry out on the large scale, 
 and added to the cost of the final products. 
 
 For the first few years the Badische Company, which had 
 acquired the Caro-Graebe-Liebermann patent, worked by mutual 
 arrangement in combination with the Greenford Green factory ? 
 
248 THE BRITISH COAL-TAR INDUSTRY 
 
 the latter having the monopoly of the English markets 1 The 
 Germans were using the anthraquinone process almost exclusively 
 this being, as you are aware, the method still in use. When 
 ordinary English oil of vitriol is used for sulphonating, a great 
 excess of acid is necessary and there is much loss owing to the 
 high temperature, so that the dichloranthracene process from this 
 point of view had the advantage. Moreover, when anthrapur- 
 purm was the mam object of manufacture it was found that the 
 product obtained by the dichloranthracene process gave much 
 purer shades than that obtained by the anthraquinone process." 
 It would have naturally occurred to Perkin in working out this 
 last process to try fuming sulphuric acid as a sulphonating agent, 
 and he did so with success; but this method, although giving 
 better results in the way of yield and uniformity of product, was 
 placed at a disadvantage here on account of the cost of the 
 turning acid. The advantages arising from this method of sul- 
 phonating are, I may remind you, an increased yield on account 
 of the lower temperature at which the acid does its work, and a 
 product which consists mainly of the monosulpho acid and 
 which therefore gives chiefly the true "alizarin" on alkaline 
 fusion. Now Germany was, at that time, the only country in 
 which the manufacture of fuming sulphuric acid was carried on 
 and this gave them a distinct advantage in working the anthra- 
 quinone process. Perkin has called attention more than once to 
 the / ta ' e , ot aia ! rs j m thj s country during the early life of the 
 artificial alizarin industry, and I cannot do better than quote his 
 own statements : 
 
 "On account of the expense and difficulty in getting Nord- 
 hausen sulphuric acid imported into this country-few vessels 
 liking it as a cargo we commenced working with ordinary 
 sulphuric acid. We usually employed four or five parts of this 
 
 f > r 
 
 ' ahzarm," consistmg chiefly of anthrapurpurin. It may be pofnted out also 
 that, owing to some peculiarity m the internal administration of the German 
 Patent Laws at that time, the rights of Caro, Graebe, and Liebermann could 
 not be secured m certain States, and so other manufacturers took up "he 
 T n f mdUS T ry u and u entered into competition with the BadLche 
 
 t0 '-n, the anthraouinone process 
 
THE FOUNDING OF THE INDUSTRY 249 
 
 to each part of anthraquinone and heated the mixture to 
 27O-28o C. . . . I find we employed this process principally 
 in our works until the middle of June 1870. We then began 
 to work on a larger scale than we had hitherto done with di- 
 chloranthracene, and carried both processes on for a time, but 
 finding the latter the more economical, partially on account of 
 the ease with which it yielded the sulpho acids with ordinary 
 sulphuric acid, we employed it almost exclusively after a time, 
 although frequently making colouring matter by the other 
 method. 
 
 " The large quantity of ordinary sulphuric acid which had to 
 be employed to convert anthraquinone into the sulpho acids, and 
 the high temperature which had to be used, causing a certain 
 amount of destruction to take place, evidently showed that it 
 was desirable to employ fuming sulphuric acid in this process. 
 In this country we found it costly, but as it was more readily 
 procurable in Germany, the manufacturers there used it. They 
 were afterwards supplied with a very strong fuming acid from 
 Bohemia, containing about 40 per cent, of sulphuric anhydride " 
 ("The History of Alizarin," /. Soc. Arts.) 1879, PP- 2 4~ 2 5)- 1 
 
 The same statement was repeated in substantially identical 
 terms in 1896. Referring to the loss of anthraquinone when 
 ordinary sulphuric acid is used, he says :- " The means of over- 
 coming this difficulty was to use fuming sulphuric acid, with 
 which anthraquinone combined at a much lower temperature, but 
 the only acid of the kind then made was the old-fashioned Nord- 
 hausen acid. We imported a quantity of this, and, of course, 
 found it to work satisfactorily, but the difficulties and expense 
 connected with the carriage and transport of this substance on 
 account of its dangerous nature supplied as it then was in large 
 earthenware bottles made it unsuitable for use in this country. 
 
 "The artificial alizarin we first made was produced by the 
 anthraquinone process, the method still used for its manufacture, 
 but the difficulty in preparing the sulphonic acid in those early 
 days just referred to caused us to turn our attention to the second 
 process I had discovered, in which dichloranthracene was used. . . . 
 
 1 The use of Nordhausen acid for the anthraquinone process in Germany 
 began about 1871; the introduction of the stronger acid referred to by 
 Perkin in the above passage is generally attributed to Koch in 1873. Dr 
 Caro informs me that he has been unable to find the authority for this 
 statement. 
 
250 THE BRITISH COAL-TAR INDUSTRY 
 
 Without this process the manufacture of artificial alizarin in this 
 country could not have been carried on with much success in the 
 early days of its manufacture " (Hofmann Memorial Lecture, 
 see p. 1 8 1, ante). 
 
 The " contact," or " catalytic," process for producing sulphuric 
 anhydride introduced about the same time in this country by 
 Messrs Chapman, Messel & Co., and in Germany by the late 
 C. Winkler, dates from 1875, so tnat Perkin's share in the 
 founding of this great industry does not consist only in his 
 having given us the practical methods for realising Graebe and 
 Liebermann's synthesis in the factory, but in having devised a 
 process which, so to speak, enabled the new industry to be nursed 
 through its infancy in this country and without which it would 
 probably not have survived that Continental competition which, 
 as Perkin has told us, first began to make itself seriously felt 
 about the end of I873. 1 By that time it was fully realised that 
 a complete revision of the plant at Greenford Green had become 
 necessary. It required enlarging and modifying in order to meet 
 the successful competition arising from the development of the 
 anthraquinone process in Germany, and a considerable expenditure 
 of capital would have been necessary to carry out this work. But 
 Perkin, whose ambition it had always been to be able to devote 
 himself to pure science, and whose personal requirements were 
 extremely modest, found that his manufacturing career had by 
 then provided him with sufficient means to enable him to retire, 
 and, rather than incur the responsibility of making a fresh start, 
 he took advantage of the opportunity for withdrawing altogether 
 from the industry. His career as a manufacturer terminated in 
 1874, the Greenford Green works having then been purchased 
 by Messrs Brooke, Simpson & Spiller, which firm, soon after- 
 wards, transferred them to Messrs Burt, Bolton & Haywood, 
 who shifted the manufacture from Greenford Green to Silvertown, 
 and ultimately from this firm the " British Alizarin Company " 
 was developed and is still at work. Perkin always wished it to 
 be known that he considered the Silvertown works as the lineal 
 descendant of the first coal-tar colour factory. 
 
 In this sketch of the founding of the coal-tar colour industry 
 
 I have necessarily limited myself to the history of the Greenford 
 
 Green factory. These works would now appear quite insignificant 
 
 in comparison with any of the great German establishments. 
 
 1 "History of Alizarin, "y. Soc. Arts, 1879 (see p. 57, ante}. 
 
THE FOUNDING OF THE INDUSTRY 251 
 
 Although for the most part fallen into disuse, they were visited 
 with feelings of veneration by a large party of our foreign guests 
 during the Jubilee Meeting in 1906. Their erection in 1857 
 and their subsequent history had marked an epoch in the annals 
 of applied science, the importance of which was known full well 
 to those who had come to this country to render homage to their 
 founder. The whole output of dyes from these works during 
 the seventeen years that Perkin was connected with them was not 
 very great as measured by modern standards. Nevertheless, it 
 may fairly be said that no single factory established in this country 
 has ever given rise to such world-wide developments, both scientific 
 and industrial. When it fell to my lot to take part in the organi- 
 sation of the jubilee celebration in 1906, it occurred to me that 
 it would be of interest to place upon record the complete history 
 of the Greenford Green factory as a colour-making establish- 
 ment, and Sir William Perkin was good enough to prepare 
 for me the following list, which has not yet seen the light of 
 publication : 
 
 THE PRODUCTS MANUFACTURED AT GREENFORD GREEN, 
 
 1857-1873 
 
 Mauve. Large quantities manufactured. 
 
 Dahlia. Ethylmauveine, C 27 H 2 3(C 2 H 5 )N 4 . HC1. Made 
 about the same time as Hofmann's violet [1863]. The colour 
 was much admired, but being very expensive was not largely 
 used. (Jour. Chem. Soc., 1879, v l- xxx v. p. 399-) 
 
 Aniline Pink. First found in washings from mauve, after- 
 wards produced by oxidising mauve with lead peroxide. It is 
 parasafranine. Made about the same time as dahlia. (Jour. Chem. 
 Soc.) 1879, v l* xxx v. p. 407.) The researches were made many 
 years before publication. 
 
 Magenta. Prepared by mercuric nitrate under a patent in my 
 name ; a communication from abroad. It was first obtained in 
 crystals in this way. (Jour. Chem. Soc.^ 1862, vol. xv. pp. 238- 
 240.) The research was made some years before publication. 
 The process was dangerous and not carried on very long. 
 
 Amidoazonaphthalene. Used in a finely precipitated form as 
 an orange, red, or scarlet pigment for calico printing, but not 
 largely. 
 
 Britannia Violet (various shades). Made from magenta, the 
 bromine compound of turpentine, and methylated spirit, or, 
 
252 THE BRITISH COAL-TAR INDUSTRY 
 
 better, purified wood spirit. At first thought to be a turpentine 
 derivative, but afterwards found to be methylated rosanilines. 
 Made in large quantities. 
 
 Perkins Green. This was an interesting compound made by 
 treating Britannia violet (blue shade) with acetyl chloride. The 
 latter was made in large quantities from phosphorus trichloride 
 and acetic acid. The phosphorus trichloride was made in cast- 
 iron retorts with iron condensers from phosphorus and dry chlorine. 
 The colouring matter was obtained in a crystalline condition, but 
 was not investigated as to its constitution. It was rather ex- 
 tensively used for calico printing when iodine green was too 
 expensive. 
 
 " Alizarin" Produced very largely, chiefly by dichloranthra- 
 cene process. It consisted of anthrapurpurin and alizarin, chiefly 
 of the former. These were also separated and sold as " scarlet 
 shade alizarin " and " blue shade," but we chiefly sold the mixture 
 known as " red shade." 
 
 Besides the above we made suitable mixtures of aniline salts, 
 oxidising agents, and copper compounds for the production of 
 aniline black. Also the colouring matters were made into " lakes " 
 by processes of our own for paperhangings and lithographic and 
 other printing inks in considerable quantities. 
 
 This list contains what may be regarded as Perkin's direct 
 contribution to the colour industry as a manufacturer. It may 
 not appear very imposing to us now, but we must read into it 
 all that it means in order to appreciate its full significance. Con- 
 sider the pioneering work in every direction that had to be done 
 in order to accomplish these results. Consider further that they 
 were achieved at the outset by a youth of about eighteen, and 
 brought to a successful termination in seventeen years by a young 
 man thirty-six years of age, and that during the whole of that 
 period, while the factory was actively at work, a continuous stream 
 of scientific research was kept going in his laboratory. Consider 
 also the stupendous consequences of the initiation of this industry, 
 and then you will realise the extent of our indebtedness to the 
 man whose labours in this field I have attempted to give you an 
 account of. I am aware that by many who regard manufacturing 
 industry from a narrowly patriotic point of view Perkin has been 
 censured for withdrawing so soon from the scene of his industrial 
 operations. The reply to this charge is obvious. He had made 
 
THE FOUNDING OF THE INDUSTRY 253 
 
 a sufficient fortune for his modest requirements, and the seeds 
 which he had sown were developing rapidly in this country. At 
 that time (1874) German competition was only just beginning to 
 make itself felt. The industry was flourishing here, and with 
 respect to France it may be said that within a very short period 
 of the founding of the Greenford Green factory, and especially 
 from the time of the discovery of magenta, the industry was also 
 in a prosperous condition there. How thoroughly this branch of 
 manufacture had its head centre in England during the few years 
 following the opening of the Greenford works may be inferred 
 from the fact that such men as Maule and (especially) E. C. 
 Nicholson, both pupils of Hofmann, had entered the industry ; 
 that in Manchester the firm of Roberts, Dale & Co. had secured 
 the services of men like Caro and Martius, who later became 
 pioneers in the German colour-making industry. Or, if we turn 
 to the actual products, we find that, in addition to those emanat- 
 ing from the firm of Perkin & Sons, Simpson, Maule & Nichol- 
 son had secured the first really valuable process for making 
 magenta, viz. the arsenic acid process of Medlock ; that they 
 had also secured the beautiful process of Girard and De Laire 
 for phenylating magenta so as to convert it into blue and violet 
 colouring matters, and that Nicholson, by his discovery of the 
 method of sulphonation, had developed these into what were 
 for many years the most important of all the coal-tar colouring 
 matters. This firm had also introduced aniline yellow (aminoazo- 
 benzene), the precursor of the basic azo dyes, and phosphine 
 (chrysaniline), 1 the first member of the acrid ine series. They 
 were, moreover, the only manufacturers of the alkylated rosani- 
 lines under Hofmann's patent. Then the firm of Roberts, Dale 
 & Co. were making picric acid, and had, through Caro, given to 
 the industry the first induline obtained from aniline yellow and 
 aniline, as well as Manchester brown or Bismarck brown. This 
 firm had also, through Martius, given us the dinitronaphthol 
 known as Manchester yellow. Cyanine, or quinoline blue, the 
 first representative of a group of colouring matters which have 
 since become of great importance as special sensitisers for photo- 
 
 1 In the 1866 catalogue of this firm, already referred to, aniline yellow is 
 priced at 25., and phosphine at 35. per oz. The Nicholson blues were, at 
 that time, sold only in solution, the price ranging, according to the brand, 
 from 155. to 305. per gallon. Solid "Regina purple" is priced at 155. 
 per oz. 
 
254 THE BRITISH COAL-TAR INDUSTRY 
 
 graphic purposes, was discovered the same year as mauve (1856) 
 by Greville Williams, who was for some time chemist at the 
 Perkins' factory, and who afterwards, with Messrs E. Thomas 
 and J. Dower, started the Star Chemical Works at Brentford. 
 This country may also claim to have been the pioneer, through 
 Crace-Calvert and Lowe, of Manchester, in the technical pro- 
 duction of highly purified phenol. 1 The first successful method 
 for printing on the fabric with aniline black was discovered and 
 patented in 1863 by John Lightfoot, of Accrington. 
 
 This was the state of affairs during Perkin's connection with 
 the industry, and, superadded to this manufacturing activity, was 
 the supremely important fact that, until 1865, the great master, 
 Hofmann, was among us, and that the laboratory at the Royal 
 College of Chemistry had become a centre of active research in 
 the chemistry of colouring matters which stimulated the industry 
 and supplied chemists for the factories. 2 Nor must it be for- 
 gotten that Peter Griess, the founder of diazo chemistry, was 
 working over here during the greater part of the same period. 
 It cannot be said that Perkin abandoned the ship in a sinking 
 condition ; on the contrary, she was steaming full speed ahead ! 
 For any scuttling that may have afterwards occurred he can in no 
 way be held responsible. 
 
 The indebtedness of the colour-making industry to the 
 founder of the first coal-tar colour factory does not, however, 
 begin and end with his career as a manufacturer. The example 
 which he has set us as a man will for all time serve to point the 
 moral that all those qualities which make for success in industrial 
 pursuits scientific ability and knowledge, inexhaustible patience, 
 perseverance, resourcefulness, and energy may be conjoined 
 with the highest and best attributes of humanity. Such was the 
 personality of the man whose labours have added lustre to the 
 scientific and industrial history of our country, and whose loss 
 touches us the more deeply as representatives of that special 
 
 1 The state of the industry here and in France five years after its 
 inauguration at Greenford Green can be ascertained from Hofmann's 
 report on the chemical exhibits at the International (London) Exhibition 
 of 1862. It is not going too far to say that during its early years the 
 coal-tar colour industry was essentially English and French. 
 
 2 Hofmann left London in 1865. From that time until the creation of 
 the Chair of Organic Chemistry at Owens College, Manchester, in 1874, to 
 which Schorlemmer was appointed, there was no professorship in this 
 department of the science in this country. 
 
THE FOUNDING OF THE INDUSTRY 255 
 
 industry which, in its present form, embodies the developed 
 results of his pioneering efforts. 
 
 ADDENDUM 
 
 As the introduction of fuming sulphuric acid played such an 
 important part in the early history of the artificial alizarin in- 
 dustry, I have thought it of interest to append the following 
 account kindly furnished by Hofrath Dr Caro. It may be 
 pointed out that the " contact " process for producing sulphuric 
 acid dates from I875, 1 and therefore subsequently to Perkin's 
 retirement, so that it was his successors who had the advantage 
 of this new branch of manufacture : 
 
 "Previously to the publication of Clemens Winkler, the 
 entire c Nordhausen Fuming Sulphuric Acid ' was manufactured 
 by John David Starck in Bohemia (in several works near Pilsen), 
 and was largely imported into England. It originally contained 
 about 20 per cent, of the free anhydride. This acid was 
 employed by Perkin in his first experimental manufacture in 
 1869 for sulphonating anthraquinone, and was afterwards in 1870 
 exchanged for ordinary sulphuric acid, 2 while we (the Badische 
 Company) commenced at this same period with the ordinary acid 
 and gradually went on increasing its strength by adding fuming acid 
 containing about 24 per cent, of free anhydride. I recollect that 
 in 1873 we used chiefly a mixture of two parts of the said fuming 
 acid with one part of the monohydrate. At the same time 
 we studied carefully the effect of the increased strength of the 
 sulphonating agent upon the separate production of the mono- 
 and disulpho-acids of anthraquinone, and I believe that at the 
 same time (1873) similar experiments were made by all German 
 alizarin makers, particularly by Gebrilder Gessert & Co. 
 at Elberfeld, and that in consequence of the superior results 
 obtained by the action of stronger acid at a correspondingly lower 
 temperature a demand was created for fuming sulphuric acid of 
 greater strengths than hitherto supplied. Thus John David 
 
 1 The patent of Messrs Chapman & Messel is dated i8th September 
 1875. Winkler's process was described in Dingier 's Polytechnisches Journal 
 for October 1875. Dr Messel gave a description of their process before 
 the Chemical Society in April 1876, but the paper was not published by the 
 Society. 
 
 2 See Perkin's statement (ante) quoted from his " History of Alizarin," 
 1879. 
 
256 THE BRITISH COAL-TAR INDUSTRY 
 
 Starck was led to manufacture the solid fuming sulphuric acid 
 containing about 45 per cent, of the free anhydride. This was, 
 I think, in 1873 or 1874. In 1875 we employed regularly the 
 fuming acid of 45-50 per cent, of anhydride. In 1877 we went 
 further in increasing the energy of the sulphonating action by the 
 employment of fuming acid of from 68 to 72 per cent, of free 
 anhydride, which we prepared by distilling the anhydride from 
 one portion of fuming acid into another portion of fuming acid, 
 containing 45-50 per cent, of free anhydride. We also distilled 
 the anhydride into the sulphonating mixture of anthraquinone 
 with fuming acid. Immediately after the publication of Winkler 
 in 1875 we commenced experimenting with his synthetical 
 process, and, after having many times changed our experimental 
 plant, we succeeded in manufacturing the fuming acid on a very 
 large scale from 1877. At about the same time other manu- 
 facturers started the manufacture of fuming acid by the 
 synthetical process." 
 
XIX.: I 9 o8 
 
 LETTER FROM PROFESSOR H. CARO TO 
 PROFESSOR R. MELDOLA, MAY 1908 
 
 THE following letter from Hofrath Dr Heinrich Caro of Mannheim, 
 formerly chemical director of the Eadische Anilin- und Soda-Fabrik, is 
 inserted here on account of its historical interest. It bears the date 
 ityh May 1908, and relates to Professor Meldolas address to the 
 Society of Dyers and Colourists on " The Founding of the Coal-tar 
 Colour Industry" (ante, p. 234). Dr Caro had undertaken to write 
 an obituary notice of Sir William Perkin for the German Chemical 
 Society, but he died before the completion of the work. Professor 
 Meldolas obituary notice from the Chemical Society's Journal (ante, 
 p. 233) was therefore translated and adopted after some curtailment by 
 the German Society (" Berichte" 1911, vol. xliv.}. The letter is 
 given in Dr Caws own words without modification : 
 
 " MY DEAR PROFESSOR MELDOLA, Having now over and over 
 again perused your excellent historical account of c The Founding 
 of the Coal-tar Colour Industry,' which you have so kindly 
 sent to me, I beg to offer to you both the expression of my 
 sincere thanks and of my great admiration. Although the main 
 object of your Presidential Address to the Society of Dyers and 
 Colourists has been to erect an everlasting monument to the 
 memory of Sir William Henry Perkin's industrial pioneering work 
 in the field of the coal-tar dyes thus supplementing your prior 
 address to the Royal Society, 1 in which you so splendidly depicted 
 the life and the scientific research work of Perkin, you have given 
 to the world more than a mere personal and biographical account 
 of the great chemist and manufacturer. In those two joint pub- 
 lications you have embodied such a fulness of historical facts, 
 
 1 Obituary Notice: the Chemical Society's notice comprises both the 
 scientific and technical sides of Perkin's work. 
 
 257 17 
 
258 THE BRITISH COAL-TAR INDUSTRY 
 
 partly as yet unknown, and commented upon by your own 
 authoritative remarks, that your Perkin Essays will for ever rank 
 amongst the most valuable contributions to the chemical history 
 of the last fifty years. You must have devoted an enormous 
 amount of thought, time, and labour in order to collect and 
 artistically to arrange the documentary evidence upon which you 
 have erected such a monumentum <ere perennis worthy of Sir 
 William Henry Perkin and his time. 
 
 " I now feel justly afraid to proceed with my own biographical 
 work on Perkin's life, which work is still in its infancy and which 
 I have been unwise to promise to the German Chemical Society. 
 You have already said everything that could be said on the 
 subject of Perkin's life-work, and it will be very difficult, if not 
 impossible, for me to discharge my task without following in 
 your wake and copying your writings. On the other hand, I 
 ought to be very thankful to you for having paved my way. 
 
 " You have kindly asked me whether I intend coming to the 
 International Congress of Applied Chemistry in London in 1909. 
 1 would certainly like to do so, and to visit once more dear old 
 England and my dear old English friends. If I were only 
 ten years younger ! But such unfortunately is not the case. 
 I dare not forget that the sun of my life is setting. With 
 my kindest regards, I remain, my dear Professor Meldola, 
 yours faithfully, DR H. CARO." 
 
XX.: i 9 io 
 
 TINCTORIAL CHEMISTRY, ANCIENT 
 AND MODERN 
 
 BY PROFESSOR R. MELDOLA, F.R.S. 
 
 (Presidential Address, Society of Dyers and Colourists : Journal of the 
 Society of Dyers and Colourists^ 1910, p. 103) 
 
 THE FIFTEEN-YEAR PERIOD, 18701885, IN THE HISTORY 
 OF THE COAL-TAR COLOUR INDUSTRY, AND ITS LESSONS 
 
 IN dwelling upon the strengthening of the bonds between science 
 and industry as one of the most important functions of this and 
 kindred societies, I am prompted by the thought that the realisa- 
 tion of the importance the vital importance of this union has 
 not been fully grasped in this country even at the present time. 
 Our industry in the course of its history has furnished abundant 
 illustration of that principle which we as a nation have not 
 thoroughly assimilated the direct practical bearing of science, 
 even in its highest and most abstract form, upon technical and 
 manufacturing operations. For more than a quarter of a century 
 I have taken every opportunity of emphasising the object-lesson 
 conveyed by the history of that branch of chemical industry 
 which immediately concerns us here the manufacture of coal-tar 
 products inaugurated in 1856 by my illustrious predecessor in 
 this chair, whose services to that industry formed the subject of 
 my address two years ago. Perkin himself did more than any 
 worker of his time to inculcate that doctrine both by precept and 
 example. It is the spirit of propagandism which encourages me 
 to belabour this somewhat jaded hobby on such an occasion as 
 the present one, when it is my privilege to be able to appeal to 
 a wider public through the representatives of an art that is well 
 to the fore in the utilisation of the resources which science has 
 
 259 
 
260 THE BRITISH COAL-TAR INDUSTRY 
 
 placed at its disposal and through the members of a Society 
 which may be congratulated on doing good service to that cause 
 which we all have at heart. So far, however, as I am concerned, 
 the preaching of the doctrine that the development of the coal- 
 tar colour industry is primarily the outcome of scientific research 
 is nothing more than the iteration of ancient history. It is 
 interesting to note in passing that it is considered necessary to 
 restate this fact from time to time with all the air of novelty. 1 
 But after all, if a principle is true, and if its truth is not generally 
 recognised, it may be desirable to freshen up the public mind 
 from time to time, if only for the purpose of reinforcing a lesson 
 which is in danger of being forgotten. From the opinion recently 
 credited to some Hungarian chemist (said to have been twenty 
 years in an English dye-house), in the organ of the Hungarian 
 Association of Chemical Industry, 2 in which both the facts and 
 their conclusions are distorted in a most remarkable way, it is 
 perfectly clear that there is still scope for reiteration. Fortun- 
 ately, it is possible for me to support the position which I have 
 always maintained by an appeal to that particularly critical period 
 in the history of the industry when I was connected with it, viz. 
 the period following the Franco-Prussian War of 1870. It was 
 soon after this great European disaster that the Continental 
 manufacturers began to get seriously to work, and some ten 
 years later we in this country and the French manufacturers ex- 
 perienced the first symptoms of serious competition from the 
 introduction of new products resulting from German discoveries. 
 Before 1870 and for a few years subsequently the list of synthetic 
 dyestuffs was a short one. Those made at Greenford Green 
 during Perkin's time (1857-1873) were given in a list published 
 in my last address to this Society (see p. 251, ante). The staple 
 products when I first entered the industry in 1870 were magenta 
 and the blues derived therefrom, the Hofmann violets, the 
 Britannia violets of Perkin, Bismarck brown, Manchester yellow, 
 indulines, alizarin, and methyl violet, the latter discovered by 
 Lauth in 1861 and manufactured in Poirrier's factory near Paris. 
 A few minor products, such as phosphine, aniline yellow, aldehyde 
 green, etc., were made by certain firms, but it is unnecessary to 
 swell the list. No good green for dyeing purposes was known, 
 and the so-called " iodine green " was too costly and fugitive to 
 
 1 See The Times' "Engineering Supplement," i;th November 1909. 
 
 2 Ibid.) gth February 1910. 
 
TINCTORIAL CHEMISTRY, 1870-1885 261 
 
 be of much use. At the time of my second connection with the 
 coal-tar colour industry, which began in 1877, the ld state of 
 affairs was beginning to change at first slowly, but with increas- 
 ing velocity and at the time of my severance in 1885 the 
 change was progressing with such speed that I foresaw the 
 approaching decline of our supremacy in that industry, and did 
 my best on every possible occasion to direct public attention to 
 the existing state of affairs. 
 
 Now it happens that the period covered by my own personal 
 reminiscences say from 187010 1885 was the most active in 
 the discovery of new types of colouring matters in the whole 
 history of the industry. I do not mean to say that no new types 
 have been discovered since 1885, or that the actual numbers of 
 individual dyes put on the market since that date may not have 
 been greater than before that date. But it is the discovery of 
 new types or of the chemical constitution of old types which is 
 the scientific achievement which precedes and prompts the 
 industrial development and furnishes the manufacturer with the 
 means of producing new compounds of tinctorial value. With 
 the unravelling of chemical structure comes suggestions for new 
 methods of producing compounds of certain specific types, so that 
 the clue furnished by the determination of the constitution of 
 one compound may lead to innumerable compounds of the same 
 type being made available for tinctorial industry. It may be 
 instructive to recall a few of the more conspicuous cases which 
 occurred during the period under consideration. By way of 
 preliminary introduction it may be well to remind you of the 
 fact that the leading idea which furnished the key to the constitu- 
 tional formulae of the organic compounds being dealt with in the 
 colour industry, was the application of what is now called the 
 doctrine of valency to carbon compounds, and especially to 
 benzene and its derivatives, by Kekule" in 1865. That epoch- 
 making idea made its way very slowly in this country, while in 
 Germany it was being rapidly assimilated. I well remember in 
 the early years of my connection with the Chemical Society, that 
 the importance of the new benzene theory was realised by only 
 a very small number of our scientific chemists ; by the technical 
 chemists and manufacturers it was openly scoffed at, and those 
 who made use of the new ideas in their writings were jeered at 
 for " knocking about benzene rings." But if our manufacturers 
 failed to see any connection between an abstract theoretical con- 
 
262 THE BRITISH COAL-TAR INDUSTRY 
 
 ception and its practical applications, this was not the case else- 
 where, and the examples which I propose to give will show some 
 of the results. 
 
 The oldest and most largely made dyestuff in the early days 
 of the industry was magenta or fuchsine, for the full history of 
 which I refer you to the books. This colouring matter had 
 been made the subject of much scientific study by many dis- 
 tinguished chemists, and its chemical composition and mode of 
 formation were well known. But its chemical constitution was 
 a mystery till the year 1878, when the problem was attacked by 
 chemists armed with a new mental weapon and, therefore, capable 
 of looking at the question from a new point of view. That 
 weapon was, of course, the Kekule theory, which had by that 
 time become part of the mental equipment of every truly scientific 
 chemist, and the chemists who paved the way for the solution of 
 this problem were Caro and Graebe, and the men who finally 
 solved it were Emil and Otto Fischer. It is only necessary to 
 state the bare facts here ; they are all recorded in history, but I 
 shall never forget the keen delight with which I first read those 
 memorable papers of 18781880, in which the Fischers proved 
 that parafuchsine and magenta were derivatives of the hydro- 
 carbon triphenylmethane and its homologue respectively. This 
 discovery settled a point which had engaged the attention of 
 chemists, from Hofmann downwards, for a period of about twenty 
 years. Turn now to the practical consequences of this purely 
 academic piece of work. The type had been revealed. Others 
 of the older dyestuffs, such as the methyl violet of Lauth, the 
 Hofmann violets, the phenylated blues, etc., were all seen to 
 belong to the same type. Furthermore, a well-known green 
 dyestufF, malachite green, discovered by O. Fischer in 1877 and 
 by Doebner (independently) in 1878 the first direct dyeing 
 green of real value and a few other greens introduced about the 
 same time or a little later, and all made by the same processes, 
 were proved to be derivatives of triphenylmethane. Then 
 followed the scientific development arising naturally from the 
 Fischers' demonstration, viz. the search, and the successful 
 search, for other methods of building up the triphenylmethane 
 type. Totally new methods were devised and new branches of 
 the industry sprang into existence. In addition to the aromatic 
 aldehyde method of Fischer, we had the so-called phosgene 
 colours, such as the Victoria blues, night blue, crystal violet, 
 
TINCTORIAL CHEMISTRY, 1870-1885 263 
 
 etc., all of which appeared in 1883. In rapid succession there 
 appeared later dyes of the same type in which tetramcthyl- 
 diaminobenzhydrol or formaldehyde played the part of con- 
 densing agents. I have taken the trouble of compiling some 
 lists (from Schultz's tables), the results of which bring out this 
 chapter of applied chemistry in a very vivid way. Before the 
 Fischers' work, there were on the market, roughly speaking, some 
 twenty dyes of this class. I refer only to the basic dyes or their 
 suJphonic acids. Many of these older dyes were not definite 
 compounds at all, but indefinite mixtures or residues and by- 
 products. Now the manufacture of magenta began on the 
 small scale in France about 1859, so that the twenty dyes (of 
 which only some fifteen can be claimed as definite products) re- 
 present a period of activity of nineteen years. From 1878 to 
 1891, the latest date in Schultz's tables for a colouring mattter of 
 this type (Green's ed. of 1894), i.e. during a period of thirteen 
 years, twenty-four new colouring matters of this class were intro- 
 duced, everyone a definite compound and some of them competing 
 with and ultimately displacing some of the older dyes of the same 
 class, which, up to that period, had been the staple products upon 
 which some of our manufacturers here had absolutely depended 
 to keep their works going. 
 
 1 now turn to another large and important group of colouring 
 matters, the discovery of which belongs to the period with which 
 I am dealing. In 1871, Professor v. Baeyer published the first 
 of a series of papers on some new types of compounds which 
 he had obtained by the condensation of phenols with phthalic 
 anhydride and which he termed " phthalems." This, as in the 
 previous case, was at first a piece of purely scientific work. 
 Now, fortunately for that country, Germany had in one of her 
 new colour factories a chemist whose services we in this country 
 had lost a man whose name will be indelibly stamped upon the 
 history of the development of the coal-tar colour industry. I 
 refer to my old friend Dr Heinrich Caro, of Mannheim. It 
 was he who recognised the technological importance of Baeyer's 
 work, and turned this " academic " chemical reaction into a manu- 
 facturing process by his discovery that the substituted phthalems 
 were possessed of great tinctorial value. Thus appeared in 1874 
 the eosins, the bromo-derivatives of resorcin-phthale'm, and I have 
 a vivid recollection of the excitement with which I first experi- 
 mented with some of these beautiful new dyes when, somewhat 
 
264 THE BRITISH COAL-TAR INDUSTRY 
 
 later, they first found their way to this country. The subsequent 
 history is substantially as before. The principle that substituted 
 phthalems were dyestuffs had been discovered ; further discovery 
 for some years turned upon methods for introducing various sub- 
 stituents into the phthale'lns, and the list was rapidly extended. 
 From this discovery of Baeyer's in 1871 there was thus developed 
 another branch of industry, creating a demand for raw materials 
 such as phthalic anhydride and resorcinol, which had never before 
 been made on a large scale. In the meantime, Baeyer and other 
 Continental chemists were slowly unravelling the mystery of the 
 chemical constitution of the phthalems, and after some years it 
 was shown that they were closely related in type to the triphenyl- 
 methane group. It may be of interest to add that the question 
 of the constitution of these compounds is still under investigation, 
 but this is a chapter of modern chemistry. The direct descen- 
 dants of these earlier substituted phthale'ins are the well-known 
 rhodamines, first introduced in 1887. 
 
 Another important group of colouring matters belonging to 
 the same period owes its origin to a discovery by Lauth in 1876, 
 viz. that certain diamines when oxidised in the presence of 
 sulphuretted hydrogen gave rise to the formation of violet 
 dyes. At first this also was a purely academic discovery ; Lauth's 
 violet never became an important addition to the list of avail- 
 able dyestuffs on account of its cost. But the same year the 
 principle was extended by Caro, with the result that methylene 
 blue was introduced. Here again I have a vivid recollection 
 of the sensation produced in this country by the introduction of 
 a new blue dyestuff. Up to that period all the known blues 
 were phenylated rosanilines. No basic blue soluble in water had 
 ever been available for tinctorial industry. The basic phenylated 
 rosanilines had, on account of their insolubility, to be used in 
 alcoholic solution, and the water-soluble blues were salts of 
 sulphonic acids. The chemical constitution of methylene blue 
 was attacked as a scientific problem by Bernthsen in 1883, and 
 successfully elucidated in a masterly series of researches which 
 bore the usual practical result. New and more advantageous 
 methods of making the colouring matter were discovered, and 
 the original methylene blue was soon followed by a number of 
 new dyestuffs belonging to the same type. 
 
 This same eventful period witnessed the introduction of 
 other great groups of colouring matters. It is unnecessary to 
 
TINCTORIAL CHEMISTRY, 1870-1885 265 
 
 restate at length histories which are already upon record. I need 
 only mention naphthol yellow or acid yellow (1879), tne oxa " 
 zines (1879), tne indophenols (1881), the new series of azo 
 colours which began with chryso'fdine and naphthol orange 
 (1875-1876), fast red, the Ponceaux, Bordeaux, and Biebrich 
 scarlet (1878-1879), blue black (1882), Congo red, the first 
 of the direct cotton dyes and the first representative of that 
 enormous series of azo colours derived from tolidine, dianisidine, 
 etc. (1884-1885). Then we had the new series of quinoline 
 dyes beginning with flavaniline (1881), and the renewed interest 
 in the safranines and allied colouring matters arising from the 
 researches of Witt and Nietzki, and the consequent introduc- 
 tion of many new dyestuffs belonging to this type beginning 
 with phenosafranine (1878), the eurodines (1879), neutral violet 
 (1880), etc. Safranine, as you will remember, was first recog- 
 nised among the products of oxidation of aniline (crude) by 
 Perkin in 1861, and his own mauve, the first of the coal-tar 
 dyes, was in later times (1888) proved by Fischer and Hepp to 
 be a member of this same series. Within this same period also 
 falls the discovery of the first method of producing the sulphide 
 colours, which have since become of such great importance 
 and which began, in germ, with the old cachou de laval of 
 Croissant and Bretoniere in 1873. So also there remain to be 
 recorded the numerous and important developments in the ali- 
 zarin group, beginning with alizarin orange (1875), alizarin 
 blue (1878), alizarin blue S (1882), etc., gallem and ccerule'm 
 (1878), the first of the hydrazine colours, tartrazine (1884) ; and 
 sun yellow, the first of the stilbene dyes (1883). And last, and 
 by no means least, we have the first indigo synthesis by Baeyer 
 in 1880, and the second (Baeyer and Drewson) two years later, 
 and the settlement of the constitution of this all-important 
 colouring matter in 1888 by this same master worker. 
 
 CHEMICAL RESEARCH THE PRIME FACTOR IN THE DEVELOPMENT 
 OF THE COAL-TAR COLOUR INDUSTRY 
 
 I have narrated this chapter of industrial chemical history in 
 the barest outline, because the details can be filled in by reference 
 to existing literature. But I have spoken of nothing of which I 
 have not personal recollection, because at that period it was my 
 regular habit to keep myself acquainted, as far as was made 
 
266 THE BRITISH COAL-TAR INDUSTRY 
 
 known through the ordinary channels of publication, with what 
 was going on in the colour industry outside our own works, and 
 specimens of the new colouring matters sooner or later found 
 their way into our laboratory. I claim therefore with some con- 
 fidence that this period of fifteen years was not only, as I have said, 
 a most eventful one, but it may even be permissible to go further 
 and to declare that it was the most critical period in the whole 
 history of the coal-tar colour industry. It was the period which 
 witnessed the introduction of nearly all the chemical types of 
 colouring matters on the market at the present time, and it was, 
 above all, the period which saw the stagnation and the commence- 
 ment of the decay of the British coal-tar colour industry. A 
 careful examination of the history of this period should therefore 
 furnish lessons of the utmost importance. What does this history 
 reveal ? In the first place, the broad fact that there was immense 
 activity in the way of discovery, and in the next place, that the centre 
 of this activity was not in this country. Consider all these new 
 types of colouring matters or every individual dye discovered 
 during the period, and it will be found that our national contribu- 
 tion to the industry was quite insignificant as compared with the 
 foreign and especially the German discoveries. The question of 
 the cause of the decline of the British industry resolves in reality 
 into the question of the cause of the Continental activity. 
 
 The answer to this last question has been staring us broadly 
 in the face for over thirty years. It is amazing that there 
 should have ever been any doubt about, or any other cause 
 suggested than the true cause, which is RESEARCH writ 
 large I The foreign manufacturers knew what it meant and 
 realised its importance, and they tapped the universities and 
 technical high schools and they added research departments 
 and research chemists to their factories, while our manufacturers 
 were taking no steps at all, or were calmly hugging themselves 
 into a state of false security, based on the belief that the old 
 order under which they had been prosperous was imperishable. 
 It is true that when the effects of the new discoveries began 
 to make themselves felt, one or two factories did add a research 
 chemist to the staff, but the number and the means of work 
 were totally inadequate. I happened to be one of them, and 
 so I speak with some practical knowledge of the conditions. 
 We were but a handful of light skirmishers against an army 
 of trained legionaries. What could three or four say half 
 
TINCTORIAL CHEMISTRY, 1870-1885 267 
 
 a dozen at a liberal estimate research chemists, working under 
 every disadvantage, do against scores, increasing to hundreds, 
 of highly trained university chemists, equipped with all the 
 facilities for research, encouraged and paid to devote their whole 
 time to research, and backed up by technological skill of the 
 highest order ? The cause of the decline of our supremacy in 
 this colour industry is no mystery it is transparently and 
 painfully obvious. In the early stages of its decadence it had 
 little or nothing to do with faulty patent legislation or excise 
 restrictions with respect to alcohol. The decay of the British 
 industry set in from the time when the Continental factories 
 allied themselves with pure science and the British manufacturers 
 neglected such aid, or secured it to an absurdly inadequate 
 extent in view of the strength of the competing forces. 
 
 It has often been asserted that the British colour industry 
 suffered from the imperfection of our patent laws. I am quite 
 prepared to admit that there is some justification for this 
 contention ; our patent laws were faulty they are by no means 
 perfect now but that is a very different thing from the assertion 
 that the imperfection of the patent laws was the main cause 
 of our decadence. This I never did and never can admit. 
 The history of that fifteen-year period refutes it. I say, and 
 always have said, that it was primarily our neglect of science 
 which was responsible for our stagnation, in precisely the same 
 way as it may be said, per contra, that it was the appreciation 
 of science which was the cause of the progress of our competitors. 
 Had our factories been creative centres, as were the Continental 
 factories had discoveries of great industrial value been pouring 
 out of research laboratories here, I cannot but believe that the 
 pressure from within would have forced the hands of the 
 legislature, and would have brought about an amelioration of 
 the patent laws long ago. Instead of attributing the decline 
 of our colour industry to the imperfection of our patent laws, 
 the argument, as it seems to me, may fairly be inverted, and 
 it may be said that the imperfection of our patent laws was 
 largely due to our want of initiative in colour industry. 
 
 TINCTORIAL ART AS A SCIENCE 
 
 But enough has been said to enforce the lesson that the 
 development of that industry which chiefly concerns our Society 
 
268 THE BRITISH COAL-TAR INDUSTRY 
 
 is the outcome of scientific research. And what is true for 
 the manufacture of those materials which the dyer and printer 
 have to depend upon is equally true for the development of 
 the processes for applying those materials. Tinctorial art is 
 as legitimately a subject for scientific research as is the discovery 
 of new colouring matters. The processes which go on in the 
 dye vat are still under investigation, and physical and chemical 
 interpretations of results which are of everyday experience to 
 the practical dyer are being sought by many scientific workers 
 pursuing many different lines of attack. This Society will do 
 well to keep in touch with this work, for the study of what may 
 be called the " inner mechanism " of dyeing is bound up with 
 some of the greatest theoretical questions of modern physical 
 chemistry. There is in this field another point of contact 
 between science and industry which it is our duty to keep ever 
 in view. Such purely abstract questions as the nature of the 
 " affinity " between fibre and colouring matter, or the relation- 
 ship between colour and chemical constitution, which are now 
 engaging the attention of some of the leading chemists of the 
 time, can no longer be ignored by the so-called " practical man." 
 The bearing of this work upon practical procedure, if not 
 immediately obvious, is as certain to make itself felt in the 
 future as were the speculations of Kekul6 and the researches of 
 the chemists of his time upon the development of the coal-tar 
 colour industry. 
 
XXL: 1910 
 
 PATENT LAW IN RELATION TO THE 
 DYEING INDUSTRY 
 
 BY A. G. BLOXAM, F.I.C. 
 
 (Journal of the Society of Dyers and Co lour 1st s^ 1910, p. 119) 
 
 DURING the past thirty years patent law has been of great 
 importance to the dyeing industry, and conversely the dyeing 
 industry has been of great importance to patent law, and the 
 industry and the law have together achieved incidentally a much 
 greater result than their mutual benefit. The whole of organic 
 chemistry has been wondrously advanced by the desire of the 
 maker of dyestuffs on the one hand to obtain monopolies of new 
 colours, and on the other hand to avoid paying royalties under 
 existing patents. 
 
 The annexed curve (fig. 3), showing the number of patent 
 specifications relating to artificial dyestuffs of each year during 
 the period 1855-1907, is not without interest. 
 
 It was in 1856 that the artificial dyestuff industry had its 
 birth. No doubt picric acid, murexide, and one or two other 
 dyestuffs were made artificially prior to that year ; I have not 
 been able to find any patents for their manufacture earlier than 
 1856 ; their existence does not appear to have led to any 
 systematic study of how to make new colours, such as has arisen 
 since Perkin's Patent No. 1984, of 1856. 
 
 The curve is compiled from the official indexes ; the indexer 
 has included two specifications, prior to Perkin's, as relating to 
 artificial dyestuffs. One of these, however, deals with a modified 
 Prussian blue, and the other with a mixture of albumen and a 
 metallic powder. 
 
 269 
 
270 THE BRITISH COAL-TAR INDUSTRY 
 
 It was not until Renard Freres patented fuchsine, in 1859 
 (No. 921/59), that the growth of this type of patent became 
 vigorous. That year produced a crop of ten, as is shown in the 
 curve relating to rosaniline dyestuffs (fig. 4). I should have 
 preferred to draw this curve for aniline dyestuffs generally, but 
 whereas it is pretty easy among the earlier patents to pick out 
 those which may properly be said to deal with aniline dyes, it 
 
 A/fZ7S7Z4Z 
 
 60 65 70 75 80 85 
 FIG. 3. 
 
 95 00 05 
 
 becomes almost impossible in later years to make this distinction, 
 because of the great differentiation that has occurred between the 
 numerous descendants of Perkin's patent. The official indexer 
 has classed Perkin's patent in the azine group, so that this patent 
 is not recorded in the rosaniline curve. 
 
 The rosaniline curve attained its maximum in 1863, and 
 then declined rapidly, touching zero in 1868 and again in 1872 
 and 1875. It will be seen that up to this latter year the artificial 
 dyestuff curve and the rosaniline curve are very similar, showing 
 
PATENT LAW IN RELATION TO DYESTUFFS 271 
 
 that for the first twenty years little else was done than the ringing 
 of the changes on aniline and its homologues. The differences 
 between the rosaniline curve and the general curve up to this 
 point are largely due to the anthracene dyestuff curve (fig. 5), 
 
 to 
 
 1 55 60 65 70 75 80 85 90 95 00 05 
 
 FIG. 4. 
 
 which sprang into being with Liebermann and Graebe's Patent 
 No. 3850, of 1868, for the manufacture of artificial alizarin. 
 
 There were also a few specifications relating to azo dyestufFs 
 in this period, it having been discovered that by treating amines 
 with nitrites, dyestufFs could be obtained (fig. 6). It was not, 
 
 25 
 
 15 
 10 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 AA 
 
 
 
 
 
 
 
 
 A 
 
 /fv 
 
 
 
 
 
 
 A 
 
 
 f\ 
 
 TJ 
 
 
 \ 
 
 / 
 
 J 
 
 vv 
 
 / V 
 
 2 
 
 
 v 
 
 55 60 66 70 75 86 85 90 95 00 
 
 FIG. 5. 
 
 however, until Griess's Patent No. 3698, of 1877, that patenting 
 received the fresh blood which it seemed to require. It was in 
 this year also that Germany adopted her celebrated patent law, 
 and it rapidly became the custom to patent in this country all 
 the more important dyestufF inventions patented in Germany. 
 
 Turning to the curve of sulphurised dyestufFs (fig. 7), Caro's 
 Patent No. 3751, of 1877, for a dye of the methylene blue class 
 
272 
 
 THE BRITISH COAL-TAR INDUSTRY 
 
 appears to have been the first, and until 1884 all the dyes thus 
 classified seem to have been of this type. In 1884 Vignon & 
 Co. patented the process of melting paraphenylenediamine with 
 a molecular proportion of sulphur and oxidising the product ; 
 several others of this type followed, but it was not until Vidal's 
 Patent No. 9443, of 1894, that sulphurised dyestuffs really made 
 a start. From 1898 to 1899 they jumped from fourteen to 
 forty-six, an increase which it would be hard to rival in any 
 
 50 
 45 
 40 
 35 
 30 
 25 
 20 
 15 
 10 
 5 
 
 
 1865 60 65 
 
 75 SO 85 90 95 
 
 FIG. 6. 
 
 r~o5 
 
 subject-matter unless it be the bicycle class ; since then, however, 
 they have steadily declined, falling to thirteen in 1907. 
 
 1880 was the year of Baeyer's first patent (No. 1 177, of 1880) 
 for making indigo. It was from orthonitrophenylpropiolic acid, 
 and it did not prove a commercial success. Ten years passed 
 before the Badische Anilin- und Soda-Fabrik patented (Nos. 8726 
 and 10,509, of 1890) the phenylglycine process, really due to 
 Heumann. Even then patenting did not become general until 
 1898 ; it attained its maximum in 1901, and is now on the 
 decline (fig. 8). 
 
 These curves, it must be said, only partially represent the 
 activity in the industry. As I have already mentioned, they are 
 limited to specifications which profess to produce the respective 
 
PATENT LAW IN RELATION TO DYESTUFFS 273 
 
 dyestuffs. Intermediate products are not included unless they 
 are described in the same specification as the dyestuff. In the 
 case of indigo in particular this makes a considerable difference 
 
 45 
 40 
 35 
 30 
 25 
 20 
 15 
 10 
 5 
 
 
 1855 60 65 
 
 is r A 
 
 FIG. 7. 
 
 in the idea one obtains of the extent of the patenting from a view 
 of the curve ; a large part of the work expended on the subject 
 has been directed to the manufacture of substances destined to 
 be finally converted into the dyestuff. 
 
 15 
 10 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 f\ 
 
 
 
 
 
 
 
 
 r 
 
 IN 
 
 
 L 
 
 J\ 
 
 w 
 
 
 ^ 
 
 ^A/\ 
 
 j 
 
 
 55 60 65 70 75 
 Fie 
 
 85 90 95 
 
 r. 8. 
 
 The azo dyestuff curve is also rather a poor representation 
 of the activity, although here it is more frequently the case that 
 intermediate products and dyestuffs are described in the same 
 specification. Probably the sulphurised dyestuff curve is most 
 free from this defect, and therefore the much greater number of 
 
 18 
 
274 THE BRITISH COAL-TAR INDUSTRY 
 
 patents in this branch is not so remarkable as would appear at 
 first sight. 
 
 Prior to 1883 provisional specifications not followed by a 
 complete specification were published, and are included in the 
 curves ; subsequent to that date only complete specifications 
 have been published, so that in comparison the number of appli- 
 cations appears smaller. 
 
 The maximum of patenting coincides with the maximum of 
 sulphurised dyestuffs, and the heavy decline of the latter during 
 the past ten years has been accompanied by a serious decline in 
 the total number of patents ; however, there has been a distinct 
 recovery since 1903, due chiefly to the increased demand for lakes. 
 
 The last decade of the nineteenth century was certainly one 
 of marvellous synthetic activity ; probably we shall see the like 
 again, but in what direction it is not easy to prophesy. Indigo 
 having succumbed, there does not seem to be any natural dyestufF 
 worthy of sustained attack from the technical standpoint. Some 
 life is at present (1910) exhibited by dyestuffs of the anthracene 
 series, but otherwise the industry may be said to be resting. 
 
 It is a matter of some surprise that the manufacturers have 
 been so eager to patent their dyestuffs. Where successful secret 
 working is possible the monopoly may be much longer than that 
 afforded by a patent, and far less troublesome in many respects. 
 
 Fortunately for the industry and for science, the manu- 
 facturers have preferred to patent ; it is sincerely to be hoped 
 that they will continue to do so, for no thoughtful man can fail 
 to realise the immense benefit which must accrue from a system 
 by which inventors are given every encouragement to pour their 
 inventions into the lap of the public, notwithstanding that there 
 is much which the public do not want. Indeed, this must be 
 regarded as the reasonable basis for a patent law. 
 
 Abolitionists in respect of patent laws are practically extinct. 
 Switzerland has succumbed, now granting patents not merely for 
 embodied inventions, but for processes. Holland abandoned 
 her fifty-year-old law in 1869, but is now about to legislate again 
 in favour of patents. 
 
 It cannot be gainsaid that industry benefits enormously by 
 the publication of inventions ; the intended benefit, namely, that 
 the public may know how to exercise the invention at the expira- 
 tion of the term of the grant, is small compared with the stimulus 
 given to fresh invention, not merely by leading the reader's 
 
PATENT LAW IN RELATION TO DYESTUFFS 275 
 
 mind into fresh fields of thought, but by the desire suggested 
 on the one hand to " go one better," and on the other hand to 
 evade the patent claim. This direct benefit to industry may 
 even be eclipsed by the indirect benefit procured through the 
 educational value of the publication. Patent specifications are 
 becoming our best technical journal, albeit one in which much 
 rubbish is printed. 
 
 It is the compulsory and immediate publication as a condition 
 of the patent grant which has led to the present highly developed 
 state of the artificial dyestuff trade and of organic chemistry. 
 
 It was largely due to the representations of Mr Levinstein 
 that the Board of Trade appointed a committee at the end of 
 1900, whose report gave rise to the Patent Act of 1902. This 
 provided a modification of the compulsory licensing clauses 
 (which did not prove satisfactory) and introduced a system of pre- 
 liminary examination, which came into force on ist January 1905. 
 
 Five years' experience of the working of this system has not 
 caused me to vary my opinion that a preliminary examination is 
 not advantageous either to the public or to the inventor. The 
 system involves a search among specifications to British patents 
 published during a period of fifty years prior to the date of the 
 patent application under examination. 
 
 A few years hence, when a considerable number of the patents 
 dated 1905 and onwards have come before the courts, we shall 
 be in a position to judge whether the preliminary examination 
 has had any effect in enabling the patentee to place more reliance 
 upon his patent. I am not hopeful that this will be the case. 
 So far six patents which have been subjected to preliminary ex- 
 amination have been before the courts, and of these only two 
 were upheld as valid. 
 
 As I have already stated, patents ought to be granted primarily 
 for the purpose of informing the public how new manufactures 
 are to be conducted. 1 think there is sometimes a slight con- 
 fusion of ideas as to the nature of the reward which is supposed 
 to be bestowed on the inventor by the patent grant. I take it 
 that the reward is a recompense to the inventor for disclosing the 
 manufacture ; it is one which must depend entirely on his own 
 exertions, since the sole profit which he can reap is in working 
 the invention himself or persuading others to work on a royalty. 
 The reward is not one for establishing a new industry or manu- 
 facture. The difference seems to me considerable ; in the one 
 
276 THE BRITISH COAL-TAR INDUSTRY 
 
 case the contract between the public and the inventor is that he 
 shall have the sole right to endeavour to establish the manufacture 
 and to continue the manufacture if established. In the other case, 
 the contract would be that the inventor should have the sole 
 right to manufacture when the manufacture had been established. 
 Provisions as to immediate publication would be useless in the 
 latter case, and, indeed, injurious both for the public, as rerfdering 
 it less likely that the manufacture would be established, and to 
 the inventor, as telling all his competitors in what direction he 
 was endeavouring to obtain the patent reward. Publication 
 would not be necessary until after the establishment of the 
 manufacture, and then only for the purpose of defining the pro- 
 tection afforded by the patent. 
 
 The patent grant as a recompense for publication ensures 
 that there shall be no chance of the public losing the increased 
 convenience, comfort, and economy due to the ingenuity of the 
 inventor. At the same time it is inexpedient that the inventor 
 should be allowed to sit on his patent rights, and thus delay the 
 public enjoyment of the fruits of his invention for the whole, or 
 a considerable part, of the term of his patent. 
 
 Partly for the purpose of checkmating the dog-in-the-manger 
 patentee, many countries adopted what is known as compulsory 
 working, the patent becoming automatically void after a few 
 years if not worked in the country. This is a very severe 
 measure ; the number of patentees who need chastisement for 
 declining to work their patents is relatively very small ; the great 
 majority of patentees yearn to have their patents worked, and 
 spend much labour in endeavouring to get them worked. Re- 
 garded as a measure against the dog-in-the-manger, this system 
 has never found favour in our country. 
 
 On the other hand, the compulsion to grant licences on 
 reasonable terms when requested to do so appears free from 
 objection, and this mode of meeting the objection under con- 
 sideration has been steadily put forward ever since the beginning 
 of the last century. The difficulty of determining what should 
 be the conditions precedent to the compulsory licence seems to 
 have been the obstacle in the way of the adoption of the mode, 
 and it was not until the Act of 1883 that any provision found 
 its way into our law. The difficulty is not yet settled, however, 
 since the amending Acts of 1 902 and 1 907 have both varied the 
 original conditions 
 
PATENT LAW IN RELATION TO DYESTUFFS 277 
 
 No system of compulsory licensing or compulsory working 
 exists in the United States. Personally I am disposed to think 
 that the system of compulsory licensing should be carried much 
 further than has been done in any country within my knowledge. 
 Why should it not be incumbent upon the patentee to grant 
 licences to all comers ? If he has spent time and capital in 
 setting up a manufacture of the invention before he is asked to 
 grant a licence, this fact must be taken into consideration in 
 settling the royalty. The patentee should have the opportunity 
 of being first in the field ; it would be only right that he should 
 not be compelled to grant a licence until his patent was of a 
 certain age. I do not see why the requirements of the public or 
 the public interest factors which it is always difficult to de- 
 termine should come into consideration. 
 
 Whatever system of compulsory licensing be ultimately 
 adopted, I am convinced that it will be found an adequate 
 substitute for compulsory working, not only in respect of pre- 
 venting the patent from becoming a true monopoly, but also in 
 respect of enforcing as far as possible the working of the patent 
 in the country of origin. 
 
 To some extent compulsory working is a corollary of pro- 
 tective tariffs. No amount of duty on an imported patented 
 article could serve to establish the manufacture of it if the 
 patentee had the power to veto the manufacture. Even in a 
 protectionist country, however, the policy of penalising non- 
 working by revocation of the patent is suicidal, so far as the 
 establishment of the manufacture is concerned. Those who 
 advocate this penalty are strangely illogical ; the patent was 
 granted, they say, to establish a new manufacture because no one 
 will embark capital in such an enterprise without some protection 
 from competition. If the manufacture is not established within 
 a certain period they would proceed to extinguish the sole in- 
 centive for establishing it. 
 
 At least the revocation should not occur until someone is 
 ready to work the invention. The position would be less absurd 
 if it were essential for the person applying for revocation to 
 show that he is ready to start the manufacture, and has a reason- 
 able prospect of an extensive trade. 
 
 To my mind, however, the greatest danger in the system of 
 revocation for not working lies in the fact that it is just the 
 patents which we require most that are most liable to revocation 
 
278 THE BRITISH COAL-TAR INDUSTRY 
 
 on this ground. It is the patent which it is difficult to work in 
 this country that is most likely to establish a new industry ; the 
 revocation of the patent will only enhance the difficulty of 
 establishing the new industry. Hence inventors of the more 
 revolutionary inventions will refrain from patenting them until 
 such time as they think there is an opportunity of manufacture 
 being started. This will greatly retard the progress due to early 
 publication and the rivalry already alluded to. 
 
 After all, the inventor is granted the patent in consideration 
 of his having introduced^ that is, disclosed, the manufacture, not of 
 his having established it. And in practice this is how it happens, 
 almost universally. The inventor gets his reward from the capital- 
 ist before the manufacture is established ; it is the capitalist who 
 reaps a reward for having established the manufacture. 
 
 If patents are possessed by foreigners in order that they may 
 have a monopoly of importing into this country, the evil as I 
 will call it, though I am far from convinced that it matters to the 
 country is remediable by allowing Britishers or other foreigners 
 to obtain easily a licence for importing. If such patents are held 
 for the purpose of preventing manufacture in this country, a 
 compulsory licence will also serve as a cure. 
 
 DISCUSSION 
 
 Dr CAIN drew attention to the difficulty of keeping the manu- 
 facture of dyestuffs secret, as had been suggested by Mr Bloxam. 
 He mentioned the case of primuline. The manufacturer of 
 this dyestuff declined to take out a patent and decided to keep 
 the process a secret. Being the first of an entirely new class of 
 dyestuffs and, moreover, there being considerable difficulty in 
 ascertaining by analysis its chemical constitution, it was thought 
 that there would be no difficulty in keeping the matter quite 
 secret. Unfortunately, three weeks after the introduction on 
 the English market of this particular colour a similar colour 
 was put on the market by a German firm. He thought that in 
 the case of sulphurised dyestuffs there would be less difficulty 
 in keeping the matter secret. He was of opinion that the cost 
 of applying for compulsory licences for the working of patents 
 in this country was the reason of their not being applied for. 
 With reference to the so-called downfall of the chemical industry 
 in England, he mentioned the fact that Hofmann had often been 
 
PATENT LAW IN RELATION TO DYESTUFFS 279 
 
 credited with the invention of coal-tar colouring matters, to 
 which he was not strictly entitled ; for example, Nicholson pre- 
 pared a number of products which were handed over to Hofmann. 
 Nicholson by phenylating rosaniline naturally suggested to a 
 chemist the methylating of the same product, the latter producing 
 Hofmann's violet. 
 
 Mr W. P. DREAPER defended the British system of chemical 
 training as compared with the Continental, and thought it was 
 more conducive to freedom of thought. In his opinion the 
 number of individual thinkers turned out in England was much 
 greater than was the case on the Continent. He thought that 
 compulsory search was to the advantage of the inventor, as he 
 was thereby enabled to go direct to the Patent Office and not 
 necessarily pass his invention through the hands of an agent. 
 
 Dr E. FEILMANN thought that the working of compulsory 
 licences might be settled in a businesslike manner, without 
 calling in the Law Officers of the Crown, the terms being 
 arrived at by the ordinary method of business bargaining, with- 
 out any interference on the part of paid officers. 
 
 Mr BLOXAM, in reply, expressed the opinion that the granting 
 of compulsory licences ought not to be anything like so costly as 
 was the case at present. He pointed out that the average dye- 
 stuff patent covered many hundreds of dyestuffs, and it was not 
 necessary to limit the specification to one particular dyestuff, as 
 was the case in the United States. He referred to the fact that 
 in the case of Levinstein, the Board of Trade made an order to 
 grant a licence, but no licence was actually granted. 
 
XXIL: 1910 
 
 THE COAL-TAR COLOUR INDUSTRY OF 
 
 ENGLAND: CAUSES OF ITS PROGRESS 
 
 AND RETARDATION 
 
 BY I. SINGER 
 
 (Journal of the Society of Dyers and Colourists, 1910, pp. 124150) 
 
 THE question " Why did not the coal-tar industry obtain a sure 
 and permanent footing in the land of its birth, and why has it 
 reached such perfection and development in Germany ? " has 
 often been asked and variously answered, according to the 
 standpoint of the critic or the occasion which called forth the 
 reflection. 
 
 In this country the high excise duty on alcohol, the patent 
 laws, high wages, the free-trade policy, want of adequate second- 
 ary education, the supposed absence of research chemists, have 
 all been mentioned in turn as being concerned in obstructing the 
 development of the colour industry. 
 
 In Germany, however, entirely different views prevail. There 
 it is boldly asserted that inasmuch as the coal-tar industry is 
 essentially of a scientific character, it as naturally was bound to 
 become a German industry. 
 
 It was to be expected of their patriotism that Germans should 
 accept this explanation as satisfactory and all-sufficient, but it 
 caused no little surprise in other countries where the problem 
 has been discussed with as keen an interest, perhaps, as in 
 Germany itself, albeit it has not been viewed through German 
 spectacles. 
 
 This is probably the reason why the editors of the Vegvhzeti 
 JLapok the official organ of the Hungarian Association of 
 Chemical Industry have asked me to state the views entertained 
 
 280 
 
CAUSES OF PROGRESS AND RETARDATION 281 
 
 in this country concerning this question. "We know," they 
 wrote, "that the Germans have written a great deal on this 
 subject, but we think it would interest our readers to have an 
 impartial statement of the opinions of the British consumers." 
 
 I responded to this appeal with an article which appeared in 
 the Christmas number of the Vegveszeti Lapok. I did not 
 attempt, however, to interpret the views of others, but gave my 
 own. In this article, originally intended for Hungarian readers 
 only, I tried to disprove certain allegations which, through per- 
 sistent reiteration rather than any inherent merits, have gained 
 currency abroad ; allegations which ascribed German supremacy 
 in this particular industry to the special aptitude of Germans for 
 scientific pursuits, and, inferentially, affirmed the want of it in 
 this country. 
 
 I pointed out not only the inadequacy, but the absurdity of 
 this explanation, and tried to show that the problem itself was 
 neither fairly nor correctly stated, inasmuch as many of the 
 assumed facts could be shown to be untrue or exaggerated. 
 
 I hoped the matter would end there as far as I was con- 
 cerned, but in this I was mistaken. An abstract of my article 
 appeared in the Chemical Trade Journal (i$th January), and thence 
 found its way into The Times (9th February) as an addendum to a 
 contributed article on " Research Chemists." Both these journals 
 were of opinion that my facts and arguments deserved some 
 attention. The Chemiker Zeitung of Coethen, however, is of 
 quite the opposite opinion, and is very wroth indeed with the 
 English Press for its indiscretion in taking notice of such abomin- 
 able heresies, since this compelled them to notice the article 
 themselves. 
 
 The most common idea is that England has lost the "coal-tar 
 colour industry through want of capable chemists. This opinion 
 finds expression in different forms. Even in this country com- 
 plaint is made that not sufficient attention is paid to chemical 
 research. The opinion seems to prevail that if more research 
 work were carried on, a larger share of the chemical industries 
 would be secured for this country. 
 
 In dissenting from this view, I do not wish to be understood 
 that I intend to disparage research work of any kind. Far from 
 it. The more there is of it the better, provided, of course, that 
 the means could be found to compensate those who would devote 
 themselves to the task. 
 
282 THE BRITISH COAL-TAR INDUSTRY 
 
 In Germany they smile at the idea of England ever com- 
 peting successfully in the organic chemical industries, because, 
 they aver, it is a pursuit which can thrive only in the hands 
 of a scientifically gifted nation. They are quite sincere in be- 
 lieving that they possess special aptitudes for work which requires 
 deep thinking, careful and patient application, and regard the 
 conquest of this industry by Germans for Germany as a 
 crowning proof of " German thoroughness " and " German in- 
 tellectuality." 
 
 This belief was interpreted with sufficient clearness by Dr 
 Duisberg at the Perkin Jubilee banquet in the following words : 
 " No other industry requires so much uniformity of thought and 
 action, science and practice, as organic chemistry or organic- 
 chemical industry. . . . We Germans possess in a special degree 
 this quality of working and waiting at the same time, and of 
 taking pleasure in scientific results without technical success." 
 
 I could quote much more to the same effect, but this should 
 be sufficient. Nor would I have noticed this delicious specimen 
 of national self-appreciation were it not that, through constant 
 reiteration, people even in this country have become infected by 
 the belief that Germany has the command of this industry 
 because of her superior education, and that if this country only 
 produced more chemists, she would thereby secure a larger share 
 of the colour industry. 
 
 Now it is not necessary to question German genius or 
 German achievements in whatever field of activity, nor to put 
 forth rival claims on behalf of the British people before one 
 may dissent from such opinions. 
 
 The most superficial reflection must disclose the absurdity of 
 any suggestion that England has lost the coal-tar industry for 
 want of sufficient acumen, or that the industry owes its present 
 ramifications solely and entirely to German intelligence and 
 industry. 
 
 To guard against any possible misunderstanding, I hasten 
 to make clear my meaning. In the above sentence I do not 
 allude to the share of the work which chemists all over the 
 world, and of every nationality, had in making organic chemistry 
 what it is to-day ; nor do I intend to belittle the intelligence 
 and industry admitted and admired the world over which 
 Germans have displayed in its industrial application. They 
 have worked well ; their results are as brilliant as they are well 
 
CAUSES OF PROGRESS AND RETARDATION 283 
 
 earned. But what I wish to insist upon is this, that all the 
 intellect and industry of a nation, however great, could not 
 possibly have made the coal-tar industry into what it is to-day 
 but for the inherent potentiality of the germ. As well ascribe 
 the widely diffused application of steam power, of electricity, of 
 railways, or the telephone to the " intelligence and industry " of 
 this or that nation. 
 
 In modern organic chemistry and organic syntheses a new 
 
 principle of wide application has been discovered, and the 
 
 enormous ramifications of this new industry must be ascribed to 
 
 this fact, and not to this or that nationality, even though it were 
 
 which it is not the monopoly of a particular race. 
 
 Great and rapid as has been the growth of the coal-tar 
 industry, it has not been more so than the spread of, say, 
 electricity, the telephone, the automobile, the typewriter, or any 
 number of industries that might be mentioned. All these have 
 grown rapidly to immense proportions because they supplied a 
 human want, because of their inherent potentialities, and not 
 because of the nationality of the people who were instrumental 
 in their creation. 
 
 Nor is it quite correct if leaving nationality out of the 
 question we credit the chemists with the creation of this 
 industry, any more than if we credited the electricians with the 
 creation of the electrical industries. At least it is as true to 
 say that these industries have called into being the chemists and 
 the electricians respectively, as that the latter have created the 
 former. The fact is that the chemists and the industry- have 
 created and stimulated each other, and the secret cause of their 
 success is the great demand for their products. 
 
 This insistence on a clear perception of the basic facts does 
 not in the least lessen the merits of our German confreres ; it 
 merely brings the different points involved into their true per- 
 spective. The Germans are known for thoroughness in every- 
 thing they do. They are as intent, as industrious, and as 
 scientific in their shipbuilding, their navigation, their spinning 
 and weaving, as they are in their colour making, and in time 
 may possibly eclipse their British cousins in all these industries. 
 But they have not done so yet. Would it not be absurd to 
 ascribe this superiority in particular industries to greater intelli- 
 gence in the British, or want of scientific attainment or thorough- 
 ness on the part of the Germans ? 
 
284 THE BRITISH COAL-TAR INDUSTRY 
 
 For it is yet to be proved that more skill, science, or patience 
 is required to make, say, benzopurpurine, than to build, let us 
 say, a Leviathan (with its hundreds of details so carefully ad- 
 justed), a Jacquard loom, a combing machine, or that miracle of 
 mechanism a spinning mule. 
 
 It is begging the whole question to say that England has 
 not progressed in the coal-tar industry because she has not the 
 chemists necessary for its cultivation. 
 
 Germany did not have them fifty years ago. If she has them 
 to-day it is because the ever-expanding industry has called them 
 into being. And if England has not to-day as many chemists as 
 Germany trained in the organic chemical industries, it is because 
 there is no demand for them. Had they been wanted the supply 
 would have been forthcoming. The nation which produced men 
 like Boyle, Dalton, Davey, Graham, Priestley, Kelvin, Faraday, 
 Darwin, Tyndall, Huxley, Babbage, Arkwright, Stephenson, 
 Watts, Bessemer, Cartwright, Ramsay, Dewar, Perkin, Meldola, 
 and a host of others famous in science, art, and literature, might 
 conceivably have supplied men capable of being taught how to 
 sulphonate a phenol or diazotise an amine as in point of fact 
 she has done to the full extent of her requirements. 
 
 But the contention is too absurd and self-contradictory for 
 serious argument. For by a similar process of reasoning might 
 be proved German incompetency in respect of such arts or 
 industries in which they are excelled by other nations. 
 
 Another popular misconception is that England has lost the 
 colour industry, or that the industry has retrogressed. Phrases 
 implying one or the other are constantly met with both here and 
 abroad, without anyone ever deeming it necessary to prove such 
 assertions. It is simply stated and accepted as common know- 
 ledge. It is a common experience, however, that few things are 
 in greater need of careful investigation and confirmation than 
 the " facts " which " everybody " knows. Most of the assump- 
 tions connected with the problem under discussion belong to 
 this class, and should be looked into before acceptance. With 
 this object in view let us look at a few facts which are none the 
 less true because everybody does not seem to know them. One 
 of these generally forgotten is that the crude product, the 
 coal tar, has to undergo many transformations before it becomes 
 a colouring matter, and that at each successive stage of manu- 
 facture value is added to the product. Now a large part of these 
 
CAUSES OF PROGRESS AND RETARDATION 285 
 
 preliminary and intermediary processes are performed in England 
 on a very extensive scale, and such products have been, and still 
 are, exported to Germany and other countries. That such 
 exports are not negligible quantities may be seen from the 
 following return for last year : 
 
 
 British Exports. 
 
 British Imports. 
 
 Raw and intermediary products . 
 Sundry coal-tar products (including 
 calcium carbide) 
 Indigo, synthetic ..... 
 Colouring matters .... 
 
 Total .... 
 
 
 
 1,630,000 
 3,007,000 
 
 341,000 
 
 
 
 95,000 
 2,319,000 
 
 117,000 
 1,803,000 
 
 4,978,000 
 
 4,334,000 
 
 Excess of exports . 
 
 4,334,000 
 
 
 644,000 
 
 So that last year the United Kingdom produced ^644,000 
 worth of coal-tar products more than her own not inconsiderable 
 requirements. 
 
 This has been true all along the whole period of the coal-tar 
 industry. That is, expressed in money value, this country has 
 always produced more than the value of her own requirements, 
 though some products she imported whilst others she exported. 
 
 Let me state here another indisputable fact, though not 
 always remembered by those who talk about the " loss " of the 
 industry, or of its retrogression, and that is that at no time, 
 from the inception of the coal-tar industry to this day, was there 
 any retrogression. Quite the contrary ; every succeeding year 
 the total output, whether in coal-tar products generally or in 
 finished colouring matters, was greater than in the preceding 
 year, and is to-day greater than at any previous time. 
 
 There can be no question, therefore, as regards the progress 
 of the industry in this country, though that progress may possibly 
 not be comparable to that of Germany. 
 
 But even here we are in need of information before we can 
 say that the coal-tar industry as a whole, as distinct from that 
 
286 THE BRITISH COAL-TAR INDUSTRY 
 
 of the finished dyestuff, has flourished more in Germany than in 
 this country. 
 
 I have no data to prove the contrary, yet I should not admit 
 this contention until some proof were forthcoming. I will state 
 my reasons. 
 
 In 1890 Gustav Schultz, in his Chemie des Stein-kohlen- 
 theers^ gave the following statistics of the quantities of tar 
 distilled for the purpose of colour making in the five principal 
 countries of Europe : 
 
 England . 400,000 tons Germany . . . 65,000 tons 
 
 France . . . 60,000 
 
 Belgium . . . 50,000 . 
 
 Holland . . . 15,000 
 
 Total . . 190,000 tons 
 
 Thus in 1890 England contributed more than twice as much 
 as all the other countries put together. As already mentioned, 
 this quantity of tar did not leave the country as such, but was 
 worked up into hydrocarbons, bases, acids, sulpho and nitro 
 compounds in fact, the manufacturing process was pushed on as 
 far as British industrial conditions permitted this to be done 
 profitably. True, none of these fall under the designation of 
 " colours," but they certainly form an integral and essential 
 part of the " coal tar " industry. 
 
 My point is this, that whilst the manufacture of these pro- 
 ducts has increased, their export has decreased. A private 
 communication to the writer by a member of a firm who are 
 among the largest makers of these products, explains this, as 
 follows : 
 
 " I am very sorry I cannot give you the figures you want 
 with reference to the amount of raw materials exported from 
 England to Germany in recent years, nor the amount of dyes 
 which are returned to this country made from such raw materials. 
 There are no available statistics for either of these figures. 
 
 "The export of intermediate and raw products to 
 Germany for aniline-dye manufacture has greatly decreased 
 during the last few years, owing to the fact that a larger pro- 
 portion of these raw materials is required for use in England. 
 The production of aniline dyestuffs in England has greatly 
 increased, while the production of raw materials has not. In 
 many instances the English works have nothing to spare of raw 
 
CAUSES OF PROGRESS AND RETARDATION 287 
 
 materials, where they were formerly anxious to export. A 
 further reason for this diminution is to be found in the formation 
 of the large German combines, who have sought to make them- 
 selves entirely independent of the English supplies of raw 
 materials." 
 
 Two facts are here confronting us. Germany is less 
 dependent now for her raw material on England, and the 
 exports of such products from this country have decreased. 
 But .this does not mean that less of them is produced, for the 
 contrary is the fact. What becomes of them ? The answer 
 is partly supplied in the letter 1 have just quoted : "A larger 
 proportion of these materials is required for use in England, 
 since the production of aniline dyestuffs in England has greatly 
 increased." 
 
 I am aware that the British exports of finished dyestuffs is 
 insignificant as compared with those from Germany. But these 
 sums would not be a true measure of comparison. To these we 
 should have to add the values of domestic consumption, which in 
 England is, of course, incomparably larger than in Germany. 
 
 But do not let us lose sight of the main issue through these 
 comparisons. My object is not to contend that England's 
 share in the colour industry is satisfactory. I merely want to 
 show that the past and present agitation having for its object 
 the expansion of this industry is proceeding on wrong lines 
 and in wrong directions, and that because of the many false 
 assumptions. 
 
 What then are the actual facts ? 
 
 1. That this country has a large and flourishing and growing 
 coal-tar industry. 
 
 2. That it has also a colour industry, which has never yet 
 lost ground, but has steadily been advancing, and is to-day 
 greater than at any previous period. 
 
 3. That England not only more than supplies her own wants 
 in coal-tar products , but even in finished dyestuffs consumed 
 the major portion is locally made. 
 
 4. That some dyestuffs are produced in this country in 
 larger quantities than in Germany. 
 
 5. That whilst some of the colouring matters that have 
 been invented in England are neglected here in comparison with 
 Germany, others that have been invented abroad are successfully 
 manufactured here. 
 
288 THE BRITISH COAL-TAR INDUSTRY 
 
 In view of such facts we can no longer allow ourselves to be 
 misled by such questions as " Why has England lost the colour 
 industry ? " or " Why has the colour industry migrated from 
 England to Germany ? " and so forth. Such leading questions 
 affirm far more than they ask and prejudice the whole problem. 
 
 It is not a fact that the colour industry has left the country, 
 or that it has lost ground. The truth is that certain parts 
 of the industry have been neglected, whilst others are 
 flourishing. 
 
 The matter for inquiry is therefore what part of the industry 
 is here neglected, and why ? 
 
 I will endeavour to give answers to these questions and show 
 that England has retained just so much of the coal-tar industry 
 as suited her own peculiar industrial conditions, and rejected 
 or neglected the rest ; that she resumed the manufacture of 
 such portions as, in the course of evolution, came within the 
 compass of these conditions ; that in this selection and rejection 
 the migration was not all in one direction ; and finally, that 
 intellectual superiority or competency on one side or the other 
 has nothing to do with this perfectly natural process of selection. 
 
 If we compare the industries which flourish in England with 
 those which have left, or are leaving the country, we shall have 
 no difficulty in arriving at the criteria by which to judge whether 
 a particular industry is congenial to local conditions or not. 
 For it is a great mistake to regard the colour industry as the 
 only one which has migrated from, or had been rejected, partially 
 or wholly, by England in the process of " selection and 
 adaptation." 
 
 Most prominent among the factors are undoubtedly the 
 economic conditions. In England wages and salaries are such 
 that an industry which does not lend itself readily to mechanical 
 manipulation and specialisation is, for that reason, more or less 
 unsuitable to the country. From this circumstance follow other 
 considerations, viz. that there must be a sufficient demand for 
 a particular article to warrant an economical outlay on buildings 
 and machinery. 
 
 What Mr C. W. Macara, the President of the Cotton 
 Spinners' Association, says of the industry of Lancashire is, 
 in substance, true of every industry in Great Britain. 
 
 He says : " The low cost of production is not due to low 
 wages and long hours of labour ; wages in Lancashire are higher 
 
CAUSES OF PROGRESS AND RETARDATION 289 
 
 and hours shorter than in any cotton-manufacturing district in 
 the world. By wages, I mean what earnings will command 
 in necessaries and comforts. The low cost of production is 
 due to an economical first outlay on buildings and machinery ; 
 to highly efficient labour ; to efficient specialisation in the various 
 processes of the industry. ... In a word, it is due to enterprise, 
 organisation, and skill." 
 
 The keynote of all this is specialisation, which presupposes 
 production on a large scale. This must not be confounded with a 
 large trade, or a large aggregate turnover. For instance, on the 
 Continent might be found factories many times larger than 
 corresponding ones in England. But they will carry on a 
 multiplicity of processes and produce a miscellany of articles 
 which in England would constitute several distinct trades. 
 
 Not only do we have in England " combers," " spinners," 
 and "weavers," as separate trades, but each of these branches 
 is again subdivided according to quality, some works confining 
 themselves to finer and others to coarser qualities of tops, yarns, 
 or cloth. Hence it is that though England is admittedly to the 
 fore in the textile industry, there are certain articles which she 
 cannot compete in that is, articles for which the demand is 
 too restricted. 
 
 And that also is the chief reason why certain branches only 
 of the coal-tar trade flourish in England whilst others are 
 neglected or have been entirely rejected. I say "rejected" 
 advisedly, as being nearer the truth than when it is alleged that 
 the industry has been " snatched " from England. 
 
 I will quote two facts in support of this contention. One 
 is to show that even if Germany were to relinquish entirely the 
 colour trade to-day, England would not make a bid for it, save 
 only for such portions as suited her peculiar conditions ; and the 
 other is to show that such portions she either has always possessed 
 or is acquiring in any case. 
 
 On the first point I cannot do better than quote Dr Duisberg, 
 although to do him justice he drew quite different conclusions 
 from the illustration. 
 
 He says : " One of the largest colour manufactories in 
 England had about ten years ago the licence for exploiting all 
 the English patents of two of the largest German colour works, 
 which at that time represented the value of many millions of 
 marks. It did not, however, in any way avail itself of this 
 
 19 
 
290 THE BRITISH COAL-TAR INDUSTRY 
 
 advantage, although the English firm had no restrictions and 
 were no worse off than the German ones, as they merely had 
 to pay for this licence a very small portion of their net profits 
 to the patentees for the working of the respective patents." 1 
 
 In this case therefore it could no longer be a question of 
 inventive faculty, for the colours were invented, their processes 
 worked out, and at the disposal of the English manufacturer, 
 who yet did not avail himself of this advantage. On the other 
 hand, we have and this is my second illustration a British 
 Alizarin Company successfully manufacturing an article invented 
 in Germany ! Why ? The answer seems obvious enough. 
 Alizarin can be made in bulk, whereas " all the English patents 
 of two of the largest German colour works" comprised, on the 
 face of it, a miscellany of articles, representing "the value of 
 many millions of marks" in the aggregate^ but not sufficient 
 trade in any single article to make it into a specialised and 
 paying industry in England. 
 
 Phenol, benzol, naphthol, naphthylamine, their nitro and 
 sulpho compounds, etc., are such articles, and they are made 
 and have been made all along in England, not only in sufficient 
 quantity to supply her own wants, but also for export. Alizarin 
 is another such article, and, though invented in Germany, has 
 been successfully manufactured in England all these years. 
 
 But let us note here that the British Alizarin Company makes 
 only those brands for which there is a large consumption : 
 alizarin red, alizarin blue, and alizarin orange ; whereas 
 in Germany a much greater variety is manufactured. We may, 
 I think, take it for granted that the proportional margin of 
 profit on these three brands is much smaller than on the others 
 of lesser consumption. Yet the firm selected these three and 
 rejected the rest. 
 
 Thus restricting itself to what might be called the " bread- 
 and-butter " articles of the alizarins, the British Alizarin Company 
 has, for the last seven years, paid 10 per cent, dividends on a 
 capital of 138,000, and that in a market, be it remembered, 
 which is as open to the German makers as to itself. In view 
 of this should we be justified in assuming that the company does 
 not make the other brands because they are more difficult to 
 produce, or because it has not the chemists at its disposal ? 
 I believe the inference that there is not sufficient demand for 
 1 Speech at the Perkin Jubilee banquet. 
 
CAUSES OF PROGRESS AND RETARDATION 291 
 
 these miscellaneous brands to make them into a paying industry 
 to be nearer the truth. 
 
 But and I wish you to note this point if a firm does 
 not think it worth while to undertake the production of such 
 articles as are already invented and at its disposal, either freely 
 or against the payment of a percentage on the net profits only, 
 why should such a firm, which exists for profit-making, keep 
 a staff of research chemists to make inventions which it would 
 not know what to do with when made ? 
 
 I imagine the answer that awaits my question. Germany 
 does so, and makes it pay. But Germany makes many other 
 industries pay which, under present conditions, could not be 
 profitable in England, and vice versa. 
 
 Again, I would remind you that I am not contending against 
 research work, nor that this or that industry is not worth 
 considering because it does not lend itself so readily to mechanical 
 exploitation. My only object is to point out the facts, so that 
 a remedy might be sought in the right direction. My point 
 is that it is neither the want of research nor shortage of capable 
 chemists that is the reason why certain branches of industry do 
 not flourish here so well as in other countries. 
 
 I will give an illustration from my own experience in support 
 of my contention. Let us take three colours that are produced 
 on the fibre : aniline black, para red, and naphthylamine 
 Bordeaux. 
 
 Appropriately enough, all three were invented in England. 
 Any difference there is in their production is in favour of 
 Bordeaux, which is certainly the easiest as well as the cheapest 
 to produce, whilst the black offers by far the greatest technical 
 difficulties. Yet, whilst of aniline black probably more is 
 produced in England than in the rest of Europe put together, 
 only comparatively little is being dyed of the red, and scarcely 
 any of the Bordeaux, though Germany is doing a considerable 
 trade in both the latter colours. 
 
 I repeat that were Germany to relinquish the synthetic colour 
 industry to-day, England would make a successful bid only for 
 those portions of it in which the consumption is sufficiently large 
 to warrant the laying down of special plant and on an extensive 
 scale ; and these branches she already possesses. 
 
 Alizarin and sulphide blacks the former invented in 
 Germany and the latter in France both became British in- 
 
292 THE BRITISH COAL-TAR INDUSTRY 
 
 dustries as soon as the market for these articles was sufficient to 
 warrant a profitable outlay for their manufacture. Synthetic indigo 
 is another such article ripening towards eligibility for British 
 manufacture, and would be certain to become in time a British 
 industry, even without the recent patent legislation which impelled 
 the German patentees to start its manufacture in England. 
 
 On the other hand, the " two of the largest colour works " 
 mentioned < by Dr Duisberg as having unsuccessfully tried to 
 induce an English colour-maker to exploit their patents may, now 
 that they are established in this country, find out for themselves 
 that some articles can be more profitably produced in Germany 
 than in England, even by the Germans themselves. 
 
 We may agree therefore with Dr Duisberg in his contention 
 that it would not materially affect England's participation in the 
 coal-tar industry, even if she revised her patent laws. Not, how- 
 ever, because as he seems to contend the industry requires 
 talents which the nation is deficient in, but because the industry 
 comprises too many articles of but limited consumption to suit 
 British conditions. 
 
 Dr Duisberg is demonstrably wrong in his classification when 
 he assigns to England industries which are purely mechanical and 
 claims for Germany those which require " scientific thought and 
 application." His idea of Englishmen in the arts is as hewers of 
 coal and minders of machines. His words are : 
 
 " Whereas, therefore, the conditions in England for many in- 
 dustries, such as for the mining industry, for spinning and weav- 
 ing, not forgetting inorganic chemistry, are far more advantageous 
 than in Germany, the latter country has the natural privilege in 
 the organic chemical industry." 
 
 There is something patronising in this sentence especially 
 when, in addition to the hewing of coal and minding of spinning 
 and weaving machines, he suddenly remembers chemistry 
 inorganic chemistry. He came well-nigh forgetting it, though it 
 represents quite a respectable turnover. For the last year the 
 exports of what is classed under " Chemicals, Drugs, Dyes, and 
 Colours" amounted to over 16,000,000, the imports to 
 10,000,000, thus leaving a balance of exports over imports of 
 about six million pounds. To this modest sum, however, we 
 would have to add the home consumption, which probably may 
 be as great as that of the rest of Europe put together. 
 
 Somehow the eminent German doctor saw the " hands " only 
 
CAUSES OF PROGRESS AND RETARDATION 293 
 
 in the British textile mills, and not the brains behind them. He 
 must have been so struck by the ease with which these machines 
 were worked that it quite escaped his notice that they had to be 
 invented, constructed, and improved until they became so 
 automatic that a child could superintend them. Yet those 
 machines can teach an eloquent lesson and illuminate for us the 
 very subject now under discussion. For it was necessity which 
 called those machines into being in a struggle for existence in the 
 strictest sense of the phrase, and the secret of their success is 
 specialisation and the division of labour, the two essential and 
 primary conditions of British industries. 
 
 In short, the question whether a particular industry is suitable 
 to English conditions does not depend on its character, whether 
 it is mechanical or chemical, organic or inorganic, requiring much 
 or little skill, but merely whether it is a bulk industry. 
 
 If you survey the field you will find that in each case where 
 an English firm takes up the manufacture of an article, it is the 
 one with the lowest margin of profit, and therefore the most 
 difficult to compete in. What is it that makes him choose thus ? 
 Not the smallness of the profit, nor the ease or difficulty of its 
 production, but the fact if I may use a slang expression that 
 there is " something to go at." 
 
 I have dealt with one large feature of the industry only, and 
 have given prominence to it because, though obtrusively present 
 in almost every important industry of the country, it is entirely 
 ignored in the discussion of this subject. 
 
 I do not pretend that it is the only reason why the colour 
 industry of this country is not greater than it is, but it certainly 
 is the chief one. Nor do I say that it is right it should be 
 so, that the country should reject every industry which cannot 
 be harnessed to a powerful engine. I only wanted to make 
 clear the fact that the tendency of British industries is towards 
 specialisation, and that, one by one, all those industries which 
 do not lend themselves to this process are being neglected or 
 eliminated. 
 
 I could name scores of industries which have left the 
 country, or are in process of leaving, for no other reason ; and 
 no amount of research work or inventions can prevent it. 
 You may ask, " Is there no remedy to arrest this ? " I believe 
 there is, but not merely by the erection of more universities 
 and laboratories. 
 
294 THE BRITISH COAL-TAR INDUSTRY 
 
 You would have to devise means of organising these lesser 
 industries in such a way that they could be exploited profitably. 
 
 If a method could be found to do this and I do not think 
 it impossible or impracticable the chemists and inventors would 
 come forth without any special creative effort. We are all 
 worried about what to do with our boys. Create the field, and 
 the workers will soon crowd around you. But it is starting at 
 the wrong end to be clamouring for the chemists when you have 
 no use for them. 
 
 DISCUSSION 
 
 Dr CAIN wished to correct the statement of Professor 
 Duisberg, which had been quoted by Mr Singer, to the effect 
 that although a British firm of aniline-dye manufacturers had 
 had the opportunity of working in this country the patents of two 
 large German firms, it had not availed itself of that opportunity. 
 He thought there was no secret as to the identity of the parties 
 referred to, and he was able to contradict the statement from his 
 own personal knowledge, and to state that hundreds of tons of 
 dyestuffs had been manufactured in this country under those 
 patents by the firm mentioned. 
 
 Mr Singer's attitude with relation to the state of the British 
 aniline-dye industry was entirely opposed to that adopted by the 
 leading authorities, such as, for example, Professor Meldola, 
 Professor Green, and the late Sir William Perkin. These 
 authorities attributed the so-called decline in the industry to 
 the lack of employment of research chemists, and to the general 
 want of education on the part of the manufacturers. He (the 
 speaker) wished to associate himself strongly with these opinions. 
 
 Mr Singer's contentions were that there had been no decline 
 in the industry in this country, and if there had it was not due 
 to the cause referred to. 
 
 It was probably true, as Mr Singer had stated, that the 
 manufacture of dyestuffs here had gradually increased, and in 
 that sense the word " decline " was not, perhaps, strictly correct, 
 but for all practical purposes it represented the state of the 
 industry as compared with that of Germany. Mr Singer had 
 shown that a consideration of imports and exports did not 
 accurately represent the amounts of dyestuffs manufactured, 
 because it did not take into account the amount, according to 
 Mr Singer a very large one, which was manufactured for home 
 
CAUSES OF PROGRESS AND RETARDATION 295 
 
 consumption. He thought, however, that no one would or 
 could deny that roughly about 95 per cent, of the dyes used 
 in England were of foreign manufacture. 
 
 That being so, the odd few per cent, could not represent 
 very much. Further, he did not agree with the lecturer's 
 suggestion that British manufacturers would not bother with 
 small manufactures, but would only take up the production of 
 dyes (or other materials) which could be made all the year round 
 with the minimum amount of expenditure on direction and 
 machinery. Mr Singer's illustration of the large quantities of 
 coal-tar products, in particular the cruder products, which were 
 produced in this country, was not a case where the British manu- 
 facturer had selected a manufacture especially suitable to the 
 economic conditions referred to. The larger quantity of these 
 products manufactured here, as compared with those furnished 
 by Germany, particularly in the past, was due to the fact that 
 we had always made much more illuminating gas in this country, 
 and, broadly speaking, Germany seemed to have jumped, in the 
 matter of illumination, from lamps to electric light. 
 
 There were dozens of dyestuffs, any one of which would 
 keep a large works going continually, but they had not been 
 made here, or, if they had, only to a small extent. What was 
 the real reason of this, and why had not a great dyestuff industry 
 arisen in this country as well as in Germany ? The cause was, 
 in his opinion, the lack of education both of the manufacturers 
 and of the people at large. The manufacturer had not in the 
 past really understood his business. He had not kept abreast 
 with scientific discovery, and did not realise the possibilities 
 of such discoveries as applied to his manufactures ; consequently 
 he did not see the enormous necessity of employing research 
 chemists. What was true of the individual manufacturer was 
 true also of the investing public. The average investor, he 
 thought, usually fought shy of investing his capital in businesses 
 concerned much with patents or the possibility of taking out 
 patents he suffered from the practical mind which often meant 
 one deficient in theoretical knowledge. He was incapable of 
 understanding the possibilities of applied chemistry, and con- 
 sequently capital flowed into other channels. This was not, 
 and had not been, the state of things in Germany. The higher 
 standard of education in Germany had had its effect on both manu- 
 facturers and investors, with the result that was seen to-day. 
 
296 THE BRITISH COAL-TAR INDUSTRY 
 
 Mr SINGER, in reply, said that his contention was not that 
 England had as large a colour industry as she might or should 
 have, but that the reasons given for this shortcoming were wrong. 
 The prevalent idea seemed to be that England has lost the colour 
 industry for want of scientific equipment. He had disproved 
 this assumption by showing that neither has England lost the 
 industry, nor has the latter retrogressed. 
 
 The facts to which he tried to give prominence were : (i) 
 that in this country inventions were disregarded unless or until 
 they related to objects for which there was an ample market ; 
 
 (2) that failing such condition, an invention would be useless, 
 and hence an increase of the number of persons engaged in 
 the making of such inventions mere waste of time and money ; 
 
 (3) inventions actually made in this country were locally neglected, 
 whilst others, made abroad, were successfully exploited here. 
 From which he would draw the inference that it was not want 
 of education at all, but the tending towards specialisation, which 
 made mass production a necessary condition. 
 
 He would put it to the test, there and then, whether his 
 reasoning had any j ustification by submitting to his hearers three 
 proposals which everybody could answer for himself. The first 
 would be to form a company for the purpose of employing 
 research chemists with a view of exploiting their inventions. 
 Would anybody subscribe a single sovereign to such a venture 
 as a business speculation ? 
 
 His second proposal would be to offer them inventions 
 already made. Having assured themselves of the genuineness 
 and utility of the invention, would not almost their first question 
 be the probable consumption of the article, with a quick calcula- 
 tion whether it was at all worth bothering with ? 
 
 But if as his third he would put before them a well- 
 considered project, no matter of what kind, which showed a 
 reasonable prospect of a fair return of profits, could it be con- 
 ceived that such a project would fail for want of talent, scientific 
 or commercial ? 
 
 The subject for inquiry was therefore to find out why in- 
 dustries which could not be harnessed to powerful engines are 
 being neglected, or by what means such industries might be 
 organised and made into paying concerns consistent with the 
 economic and social conditions of the country. That is the 
 direction in which a solution of the problem under discussion 
 
CAUSES OF PROGRESS AND RETARDATION 297 
 
 must be sought. Dr Cain had stated that he could mention 
 dozens of dyestuffs that would keep a large works going con- 
 tinually, but which had not been made here. He did not doubt 
 it. But would Dr Cain suggest he could not find the men here 
 to make them ? Surely not. Whatever may be the cause or 
 causes of the neglect of a particular industry, it cannot be the 
 want of talent, since that is always forthcoming in response to 
 the demand for it. He (the speaker) was at one with Dr Cain 
 in desiring more education and more research work ; but he 
 doubted whether these in themselves would advance the colour 
 industry. He was rather inclined to think it was the other way 
 about that the expansion of the colour and allied industries 
 would, by creating a greater demand for chemists, assist in their 
 creation. 
 
XXIII. : 1914 
 
 THE ARTIFICIAL COLOUR INDUSTRY AND 
 ITS POSITION IN THIS COUNTRY 
 
 BY F. M. PERKIN, PH.D., F.I.C. 
 
 (Journal of the Society of Dyers and Colourists, loth November 1914, p. 339) 
 
 THE coal-tar industry was founded by my father, and in the 
 early stages of the work he received much encouragement from 
 Messrs Pullar, of Perth, particularly from the late Sir Robert 
 Pullar, the father of the present President of the Society. It is 
 doubtful whether, without that encouragement, he would have 
 commenced to manufacture the product he had discovered. 
 
 I will in the first place give a brief historical outline of the 
 commencement of the industry, then reasons why it ultimately 
 in a large measure passed to the Germans, and finally how it may 
 be possible, in part at any rate, to resuscitate the industry. The 
 views given are my own opinions, but I give them for what they 
 are worth. 
 
 In the Easter vacation of 1856 my father, who was at that 
 time just eighteen years of age, having been born on I2th March 
 1838, found that when aniline sulphate was acted upon by 
 potassium dichromate a black precipitate was obtained, and on 
 examination the substance was found to be "aniline purple or 
 mauve." This particular work was carried out in a rough 
 laboratory, which he had fitted up in his father's house, known 
 as " King David's Fort," at Shadwell, in East London. 
 
 As a matter of fact, the actual discovery of the dye was an 
 accident. The aim which my father had in view was the syn- 
 thesis of quinine. With our present knowledge we know that it 
 would not be possible to synthesise quinine simply by the oxida- 
 tion of aniline, but in those days, when organic chemistry was in 
 
 298 
 
THE INDUSTRY IN THIS COUNTRY 299 
 
 its infancy, the assumption appeared quite probable. In 1856 
 it seemed quite legitimate to assume that a natural product might 
 be synthesised if the elements composing it could be brought 
 together in the right proportions. 
 
 Now, although the actual discovery of the dye was an 
 accident, it required a mind of particular aptitude to work up a 
 dirty black substance, to extract the dye, and afterwards to carry 
 out the laborious work which was necessary to prove that it was 
 a dye and could be used in place of dyes obtained from natural 
 products. I wish to lay stress on this, because the average 
 person the "man in the street" is apt to think that the dis- 
 covery of a substance is the main point. It is really not the 
 discovery of a new substance which is the chief thing, for 
 thousands of substances have been discovered which have been 
 put on one side as useless until the inventive mind came along 
 and opened out new branches of industry. 
 
 My father, having discovered this unprepossessing black 
 material, instead of throwing it away, experimented and found that 
 a brilliant colouring matter could be produced from it which had 
 the properties of a dye, and which resisted the action of light 
 remarkably well. Samples of silk and cotton were dyed with it 
 and sent to Messrs Pullar, of Perth, who, after examining them, 
 wrote on I2th June 1856 : 
 
 " If your discovery does not make the goods too expensive, it 
 is decidedly one of the most valuable that has come out for a long 
 time. This colour is one that is wanted in all classes of goods, 
 and could not be obtained fast on silks, and only at great expense 
 on cotton yarns .... and does not stand the tests that yours 
 does, and fades by exposure to air." 
 
 After further experiments, a patent was taken out (No. 1984, 
 1856), and it was decided to commence manufacturing. In June 
 1857 the building of the works was begun. In December of 
 the same year, the technical difficulties of manufacturing nitro- 
 benzene from benzene having been overcome, also the manu- 
 facture of aniline on a large scale from nitrobenzene, and finally 
 the oxidation and preparation of the dye, aniline purple, or 
 Tyrian purple as it was then called, was put on the market and 
 used for silk dyeing in the dyehouse of Mr Thos. Keith, of 
 Bethnal Green. 
 
 In introducing the new colour, an enormous amount of experi- 
 mental work had to be carried out. Mordants for use in cotton 
 
300 THE BRITISH COAL-TAR INDUSTRY 
 
 printing had to be devised. Many experiments were necessary 
 before satisfactory results were obtained in dyeing wool and 
 silk with this new dye. It was, in fact, all pioneering work 
 from purifying the raw material and devising new plant, to finally 
 applying the new product. 
 
 In connection with the raw product benzol it is interesting 
 to note that it was manufactured only in small quantities in 1856, 
 and that the price was 55. per gallon for a comparatively crude 
 product, which had to be distilled before it could be used. The 
 coal tar itself was a drug on the market, and a great nuisance to 
 the gas manufacturer. With the advent of the aniline dyes, 
 and the consequent call for more and more of the products 
 contained in the tar, the conditions changed and by degrees tar- 
 distilling plants were erected, and became a source of profit to 
 the gas manufacturer. 
 
 The introduction of a new colour from a novel source 
 naturally attracted a great deal of attention, and as a consequence 
 many workers came into the field and a large amount of research 
 work was carried out with aniline and allied products, and the 
 number of synthetic dyes gradually increased. The second 
 aniline dye, magenta or fuchsine, was discovered in France by 
 Verguin, in 1859, who produced it by heating commercial aniline 
 with tin tetrachloride. In these early days quite a number of 
 British patents were taken out, although of course a great deal 
 of work was being carried on on the Continent. It must also not 
 be forgotten that a large amount of pioneering work was instituted 
 under the direction of the German chemist, Professor Hofmann, 
 at the Royal College of Chemistry, London. In fact, the in- 
 fluence of Hofmann was of enormous value, as he imbued his 
 students with a love of research, and taught them the importance 
 of thoroughness in their work. The Germans, recognising 
 Hofmann's great gifts, ultimately induced him to return to his 
 native land as a Professor at Berlin University. 
 
 In the early days of the aniline-dye industry, probably 
 owing mainly to the influence of Hofmann, there were many 
 German chemists in English works, a number of whom returned 
 to Germany and have most materially helped the German colour 
 industry. 
 
 My father's works at Greenford Green in Middlesex were 
 the first coal-tar colour works, but quite a number of other works 
 sprang up within a few years. Some of these no longer exist, 
 
THE INDUSTRY IN THIS COUNTRY 301 
 
 but others are still with us and are of considerable size, employ- 
 ing a large number of hands. 
 
 A short time after the Greenford Works had been founded, 
 Messrs Simpson, Maule & Nicholson commenced to manu- 
 facture dyes, Edward Chambers Nicholson, one of the partners 
 and a student of Hofmann's, being a chemist of high attainments. 
 Simpson, Maule & Nicholson were originally manufacturers 
 of fine chemicals. When mauve was produced, they took up 
 the manufacture of nitrobenzene and then aniline, and gradually 
 developed into manufacturers of dyes, being the first, 1 believe, 
 to manufacture rosaniline in this country, and producing it in a 
 high state of purity. 
 
 Messrs Roberts, Dale & Co. began working before 1860. 
 Levinstein's commenced in a small way in 1864. Read Holliday 
 & Sons, Williams Bros., and Dan Dawson all commenced about 
 1865. From the first all these firms employed highly trained 
 chemists who, by their research work, did much to place the 
 industry on a strong basis. Many of the chemists, however, 
 were Germans who, as already mentioned, ultimately returned to 
 the land of their birth and, for reasons which will be mentioned 
 later, it was not possible to replace them by men of equal calibre. 
 The names of a few of these German chemists, who did so much 
 valuable work in England, may be mentioned : Dr Caro, who 
 ultimately became chief chemist to the Badische Anilin- und Soda- 
 Fabrik ; Dr Martius, who was later appointed chief chemist to 
 the Berlin Actiengesellschaft ; Peter Griess, the discoverer of the 
 diazo reaction (chemist to Allsopp's Brewery at Burton-on- 
 Trent) ; and Dr Otto N. Witt, who became Professor of 
 Chemistry at the Charlottenburg Technische Hochschule. 
 
 Up to 1875 * ne British industry was in a flourishing con- 
 dition, and fairly held its own against foreign competition ; and 
 a very large number of important patents were taken out in 
 this country. For example, Dr David Price, in 1859, patented 
 violine, purpurine, and roseine, which he obtained by oxidation 
 of aniline with lead peroxide. Medlock took out a patent in 
 1860 for magenta. In the same year, Greville Williams dis- 
 covered quinoline blue, afterwards known as cyanin. Patents 
 for violets were taken out in 1860 by Dale and Caro, and by 
 Smith and Coleman. In 1862 Perkin patented another series 
 of violets, and in 1863 Hofmann discovered a violet known as 
 Hofmann's violet, which was manufactured by Simpson, Maule 
 
302 THE BRITISH COAL-TAR INDUSTRY 
 
 & Nicholson. Aniline black, probably the fastest of all blacks, 
 was discovered by Lightfoot in 1 863. It is unnecessary to further 
 enumerate. 
 
 A very great stride in organic synthesis was made in 1867 by 
 the German chemists, Graebe and Liebermann, who showed that 
 the vegetable dye, alizarin, could be prepared by fusing dibromo- 
 anthraquinone with caustic potash. They patented this process, 
 but it was far too expensive to be of commercial importance. 
 
 My father, when with Hofmann, having had special experience 
 of anthracene, and having kept considerable quantities from the 
 time when he was a student, was naturally much interested that 
 anthraquinone, which is obtained from anthracene, could be 
 converted into alizarin. He therefore studied the matter 
 further, and found that alizarin could be produced by sul- 
 phonating anthraquinone with fuming sulphuric acid and then 
 fusing with caustic soda. He also devised another method which 
 consisted in chlorinating anthracene and then treating with 
 sulphuric acid and afterwards with caustic soda. On treating the 
 melt obtained by one or other of these methods with acid, a 
 yellow precipitate was obtained, which dyed madder mordants 
 with the greatest ease. 
 
 All the alizarin used had, up to this time (1869), been pro- 
 duced from the root of the madder plant. This then was the 
 first synthesis of a natural or vegetable colouring matter. 
 
 At the same time that experiments were being carried out 
 in England, the German chemists, Caro, Graebe, and Liebermann, 
 were also investigating the subject, and discovered the sulphona- 
 tion process about the same time as Perkin. Although the 
 patents were filed within a day of each other, artificial or synthetic 
 alizarin was first manufactured in this country, and until 1874 
 the Germans sent very little into the United Kingdom. 
 
 In 1868 the amount of madder root produced was estimated 
 at 70,000 tons a year, but in a few years the artificial product 
 almost completely replaced the natural colour, and madder 
 ceased to be grown. The total output of alizarin from the 
 madder root was about 750 tons in 1868, but in 1912 the out- 
 put of the synthetic product had risen to about 2000 tons, four- 
 fifths of which was manufactured in Germany. 
 
 The development of this branch of the coal-tar colour 
 industry was thus described by my father in his Hofmann 
 Memorial Lecture in 1896 : 
 
THE INDUSTRY IN THIS COUNTRY 
 
 303 
 
 "Before the end of the year 1869 we had produced i ton 
 of this colouring matter in the form of paste ; in 1870, 40 tons ; 
 in 1871, 220 tons; and so on in increasing quantities year by 
 year. As we had been successful in producing artificial alizarin, 
 others did not run much risk in following our lead ; yet up to 
 the end of 1870 the Greenford Green works were the only ones 
 producing artificial alizarin. German manufacturers then began 
 to make it, first in small and then in increasing quantities, but 
 until the end of 1873 there was scarcely any competition with 
 our colouring matter in this country." 
 
 He then went on to say and the remarks were not only 
 directed to his own work but to the work of other firms, notably 
 Simpson, Maule & Nicholson, who for some years were the 
 largest coal-tar colour producers in the world : 
 
 " From the foregoing it is seen that, as in the case of the 
 aniline colours, all the pioneering work connected with the 
 foundation and establishment of this branch of the coal-tar 
 colour industry was also done in this country. 
 
 " For the due development of this industry, it was necessary 
 not only to attend to technical processes, but also to carry on 
 scientific research in connection with it." 
 
 The neglect of scientific research during the next decade was the 
 reason why the coal-tar colour trade ^ established as it was in this 
 country^ gradually got forced out by German competition. 
 
 In 1874 the Greenford Works were sold to Messrs Brooke, 
 Simpson & Spiller, the manufacture of alizarin being taken 
 over at a later date by the British Alizarin Company. 
 
 I have seen it in the Press, and have also heard it in con- 
 versation, that it was not a very patriotic step to dispose of a 
 successful works at the early age of thirty-six. The reasons for 
 doing so were practically these. My father and his brother had 
 had a very difficult fight to establish the works, and had at last 
 reaped some benefit from their struggle. The use of aniline 
 and alizarin dyes was increasing by leaps and bounds, and 
 their agents all over the country were urging them to increase 
 their output largely. This practically meant doubling the size 
 of the works ; and this again meant that they would have to 
 sink most of the capital which they had made, in bricks, mortar, 
 and machinery. Although my father preferred a quiet life in 
 which to devote himself to research work, the increasing of the 
 works would probably not have been an insuperable difficulty or 
 
3 o 4 THE BRITISH COAL-TAR INDUSTRY 
 
 prevented him from carrying on the business ; but the necessity 
 of having more trained research chemists, if the works were to 
 be carried on satisfactorily, became increasingly apparent. It 
 was not possible for one brain, however energetic and fertile, to 
 carry out all the necessary research required in a large works. 
 Research chemists, however, could not be obtained. Our 
 universities did not train them. True, Germans could be had 
 at moderate salaries ; but German research chemists, after they 
 had obtained a thorough knowledge of the processes, had a 
 tendency to go back to their own country, where they were 
 received with open arms and offered high salaries by the German 
 companies. 
 
 In an industry such as that of the aniline dyes, continual 
 change is necessary. Consequently, a number of highly trained 
 research chemists must be employed, and it is the works which 
 can turn out the largest number of new colours, and at the same 
 time improve the methods of manufacture and the quality of the 
 older ones, which will obtain the market. 
 
 This is what the Germans have done. It is not correct to 
 say except to a limited extent that they have stolen the 
 artificial colour industry from us. There certainly has been a 
 lot of piracy. In the early days of the industry, German patent 
 laws were, to say the least of it, chaotic, each State either having 
 its own laws or its own ideas as to the administration of the 
 patent laws. Therefore, for all practical purposes, no patent law 
 existed. It followed, consequently, that the Germans had the 
 brains of the world at their disposal and they had to pay no fees 
 for their use. The moment a patent was published it was seized 
 upon by the German firms. If a process was worked secretly, 
 the Germans, either by research work or by other means, dis- 
 covered it and appropriated it. The products manufactured by 
 them were sent into this country ; it was vain to prosecute their 
 agents, because when the Germans found this was being done 
 they supplied the goods direct to the consumers. They sent 
 their travellers, many of them skilled chemists, all over the world. 
 They were therefore able to show how the dyes were best 
 employed. The British manufacturers were, as a rule, content 
 with issuing circulars to their customers, warning them not to 
 use inferior foreign goods. As a matter of fact, the goods, as a 
 rule, were not inferior to the British, and were often cheaper. 
 It is, however, an undoubted fact that the German colour works, 
 
THE INDUSTRY IN THIS COUNTRY 305 
 
 when they were first founded, stole the work of English brains. 
 The British Government protected their processes by allowing 
 them to take out patents in this country which they were not 
 required to work. On the other hand, German patents were 
 refused to the British inventors. This was the case with the 
 alizarin patents ; they were granted to Germans in England, but 
 refused to Englishmen in Germany. 
 
 I do not think that the German competition with alizarin 
 was very serious until after 1874, because, up to that time, it 
 could be manufactured and sold at a good profit at a price which 
 did not admit of much German undercutting. Shortly afterwards 
 the price of the alizarin paste in this country was raised, and 
 this gave the Germans their chance, which they seized with 
 characteristic energy and undersold the English manufacturers. 
 The English policy should, of course, have been in the opposite 
 direction, to keep the price low, particularly as the Germans were 
 getting in a position to supply the whole demand, if they could 
 only obtain the trade. As a matter of fact, by combining together, 
 the German manufacturers for a time practically killed the 
 British alizarin industry, and had it not been for the Turkey 
 Red Dyers' Association, who combined to manufacture alizarin, 
 the trade would probably have entirely left the country. At any 
 rate, the Germans have made very great profits, and employed 
 these in the first case to write off their capital expenditure, and 
 secondly to reconstruct and equip their works with magnificent 
 laboratories, staffed with skilled research chemists. The patent 
 laws, until the Bill of 1907 was passed, allowed foreign nations 
 to patent any process in this country simply to prevent us manu- 
 facturing, while we, if we patented abroad, must manufacture the 
 product in the particular country in which the patent was taken 
 out within a reasonable period, or else grant a licence. 
 
 In 1907 the Patent Laws Amendment Act was passed, in 
 which it was made compulsory for a foreign patentee either to 
 work his patent in this country, or else to be compelled to grant 
 a licence. Unfortunately, many loopholes for evading this Act 
 have been discovered, and it has not been so successful as was 
 anticipated. 
 
 With our own patent laws against us, the Germans made the 
 most of it. But the German spy system, of which we have seen 
 so much recently, was also against us. In many cases, however, 
 our want of business method and always our disdain of research 
 
 20 
 
306 THE BRITISH COAL-TAR INDUSTRY 
 
 work were against us. After a process was once started it was, 
 and even to-day is, largely worked by rule of thumb. I grant 
 you there is a stirring amongst the dry bones, yes, a great stirring, 
 but if we are going to take our place in the manufacture of 
 aniline dyes and fine chemicals, the stirring will require to be 
 very much more vigorous, and unless, after being stirred, the 
 bones are going to be jointed together, little ultimate good will 
 result. 
 
 I have pointed out how the Germans, owing to our patent 
 laws, were able to make use of our brains, and one cannot help 
 thinking how fertile those brains were with new ideas, and with 
 initiative to carry out the ideas from the experimental to the 
 manufacturing stage. It must be remembered, however, that the 
 number of these pioneers was not very great, and it is small 
 wonder if, when they found their ideas being exploited by others, 
 they were inclined to lose interest, and retire from the fray. 
 Whether or not this was the case I am unable to say, but in this 
 particular line of industry we seemed to lose our pioneering 
 interest. The existing works in some cases, at any rate, began 
 to live on their past reputation and seemed to make very little 
 effort to compete with their German rivals. On the business 
 side they did not take sufficient trouble to keep their customers 
 or to open out new markets. The dyer was told, if not in words, 
 at any rate by action or want of action, " These colours have 
 always been admired and have been manufactured by us for years, 
 we don't see any reason for altering the shades or the methods 
 of dyeing." 
 
 In the meantime, however, the Germans were flooding the 
 markets with new dyes and new shades and sending round their 
 travellers by the score. These travellers were not simply sales- 
 men, but in many cases trained chemists, who were prepared to 
 go into the dyehouse and show the dyer how to apply the dyes. 
 
 The question of capital also had a great deal to do with the 
 advancement of the artificial colour industry abroad. In this 
 country all the firms were privately owned, being more or less 
 family concerns. To-day this is in the main still the case. In 
 Germany it was and is otherwise. They are big commercial 
 concerns, supported by outside capital and also by the banks. 
 Furthermore, a large slice of the profits has always been put by 
 for developing the works, for new machinery, and for research 
 work. We in this country have been too prone to take too 
 
THE INDUSTRY IN THIS COUNTRY 307 
 
 much out of the business, instead of building up large reserves. 
 One might say, why then was not outside capital brought in to 
 increase the size and output of the works ? The reason probably 
 was this that capital found a more remunerative opening in 
 shipping industries and the building of docks, the opening up 
 of coal mines, in the heavy chemical trade, and in engineering 
 concerns, etc. Also a large amount of capital was invested 
 abroad to finance British or foreign undertakings from which 
 good profits could be obtained. 
 
 One of the chief causes of our not being able to hold the 
 artificial colour industry which had been founded in this country, 
 and the real cause of the German pre-eminence, and for which 
 they deserve every honour, was the lack of industrial research. 
 One of the reasons why so many of the students of Hofmann 
 rose to such eminence was the love of research with which he 
 imbued them. To-day our manufacturers are awakening to the 
 need and value of research, but for many years, although a 
 chemist was attached to most of the works, he had in the main 
 simply routine work to pursue, which either gave him no time 
 or incapacitated him for research, and this is still largely the case. 
 Small wonder is it that our manufacturers were unable to compete 
 with the Germans. In the German works, shortly after their 
 foundation, magnificent laboratories with all the latest scientific 
 apparatus were erected. Libraries stocked with the latest literature 
 were installed everything was there which might be required for 
 the investigations in hand. 
 
 Having made these preparations, chemists were employed 
 who had had a thorough training. Before they could take their 
 degrees it was compulsory that they should carry out an original 
 investigation along some line of research. The engineers employed 
 were also highly trained men with a good chemical knowledge, 
 many of them having received a university education. In the 
 works the chemist and engineer worked hand in hand. Thus, 
 when the chemist had discovered some new material or process 
 in the laboratory, it was further worked out in collaboration with 
 the engineer-chemist. The product first produced in the laboratory 
 was next made on a semi-commercial scale, and if this proved 
 successful, the commercial plant was erected and the material 
 manufactured in bulk. 
 
 As the output of the works increased, so the number of 
 chemists taken into the works increased until, as is well known, 
 
3 o8 THE BRITISH COAL-TAR INDUSTRY 
 
 some works, such as the Badische, and Meister, Lucius & Brun- 
 ing, employ over two hundred research chemists. The fact is that 
 almost the whole of the technical staff are more highly trained than 
 is usually the case here. There is also in Germany a much closer 
 relationship between the professors of chemistry in the universities 
 and polytechnic institutes and the manufacturers. This is good 
 for the professors and good for the manufacturers, as it reacts 
 upon the training of the student. 
 
 How could British manufacturers who, if they did not scorn 
 research did not recognise its value, compete under these con- 
 ditions ? During the last decade British colour makers have 
 been holding their own in certain lines, and even improving their 
 position, owing to the fact that they have been increasing their 
 technical staff. But they have been, and are, severely handi- 
 capped by the enormous German advances and by the great 
 variety of products the Germans have been able to supply to 
 the consumers. The agent of a German firm can go to the dyer 
 and offer him all the shades he requires, the British manufacturer 
 can only supply a few : consequently, the German gets the order 
 it saves so much trouble. 
 
 There are other reasons which are more closely related to the 
 German business methods, but I will not go into these, as I do 
 not wish to enter into controversial matters. 
 
 I am not fond of the expression, " War on German Trade." 
 Is it not better to say, " Opportunity for British Trade and the 
 Capture of New Markets " ? The Germans thoroughly deserve 
 the pre-eminent position which they have attained in the artificial 
 colour industry. It is in the main due to painstaking research, 
 backed by thorough business organisation. Some of their 
 business methods, it is true, are such that we should not care 
 to see them copied here, but the main reason has been the lack 
 of research, and of making opportunities, instead of waiting for 
 them to come. 
 
 Did not the Germans deserve to capture the indigo industry ? 
 The research on this subject was carried out on a truly colossal 
 scale. Many chemists were engaged for a period of over twenty 
 years upon research work in order to produce this product syn- 
 thetically on a commercial scale at a price which would compete 
 with, and even undersell, the natural product. It is stated that 
 before a single pound of synthetic indigo was placed on the 
 market over 1,000,000 had been spent during the twenty years. 
 
THE INDUSTRY IN THIS COUNTRY 309 
 
 The literature, patent and otherwise, upon the subject is one of 
 the finest chapters in the history of chemical technological re- 
 search. It is not my intention to enter into the details of this 
 magnificent work time will not permit, and most of you are 
 familiar with it. Had the indigo planters not been so sure of 
 their position, they would when the first discovery of synthetic 
 indigo was announced in 1878 have carried out experiments to 
 see if they could not improve the quality and quantity of their 
 product, but they sat by with folded hands. When it was too 
 late they cried out that the introduction of synthetic indigo was 
 a bolt from the blue. They should have watched the signs, in 
 which case they would not have been so surprised ; aye, they 
 might even have arrested or retarded the falling of the bolt. 
 
 I have given some of the chief reasons why the artificial colour 
 industry was lost to this country. There is, however, another 
 one. In the preparation and purification of some of the dyes, it 
 is necessary to employ large quantities of pure alcohol. The 
 enormous cost of pure alcohol in this country, compared to its 
 cost in Germany, owing to Government duty and excise re- 
 strictions, has made its use on a large scale prohibitive, and has 
 most certainly been a contributory cause in helping the German 
 manufacturers. Within the last few years these restrictions 
 have been considerably mitigated largely owing to the per- 
 severing efforts of Mr Thomas Tyrer. Unfortunately, much yet 
 remains to be done. Although Government has given relief, 
 the officials who have to administer the Government Acts seem 
 to forget they are public servants, placed there for the good of 
 the country. Several manufacturers to my knowledge, after 
 inquiring into the matter, found the use of alcohol so hedged 
 and bound about with red tape and officialism, that they were 
 unable to take advantage of the Act. In the fine chemical trade, 
 that is the manufacture of drugs and photographic chemicals, 
 the use of pure alcohol is of even greater importance than in the 
 colour industry. The fine chemical trade in synthetic drugs and 
 photographic chemicals never has been a British industry. It is 
 entirely due to German research work, and we have never tried 
 to develop it here. It is, however, a very important industry, 
 and there is no reason why it should not now be developed, at 
 any rate in a partial state, in this country. Alcohol, however, is 
 a very important reagent for this industry. British manufacturers 
 can produce good cheap alcohol, if there is a demand for it ; but 
 
310 
 
 THE BRITISH COAL-TAR INDUSTRY 
 
 while its use is hedged with difficulties, those who use it will 
 employ it in minimum quantities only. Like most commodities, 
 it can be made more cheaply in large than in small quantities. 
 
 Let me now briefly summarise the causes which have led or 
 contributed to the present position of the artificial colour industry 
 in this country : 
 
 (1) The character of the British patent laws and the want of 
 
 patent laws in Germany, whereby the Germans were 
 able to exploit our brains. 
 
 (2) Slackness on the part of the early British manufacturers 
 
 (after a certain period of prosperity). 
 
 (3) Industrial chemical research carried out in Germany, but 
 
 neglected by us. 
 
 (4) German business organisation. 
 
 (5) Restrictions on the use of alcohol. 
 
 That the artificial colour industry is in a bad position is self- 
 evident. A devastating war has broken out, stopping our supply 
 of imported colours, and what is the result ? There is a dye 
 famine. Dyers cannot carry out their contracts because, although 
 willing to pay almost any price, they cannot obtain the dyes. It 
 must be remembered also that aniline dyes are used for a great 
 many purposes other than that of dyeing textiles. Paper, leather, 
 bones, feathers, straw, grasses, etc., are all dyed with aniline dyes. 
 They are employed for dyeing wood, particularly in the furniture 
 trade. Very large quantities are used in paints in the form of 
 lakes. Even in confectionary they are employed. All these 
 industries are hit. 
 
 So dependent, indeed, are our manufacturers upon dyes, that 
 the stoppage of the supply is beginning to cause great distress 
 amongst thousands of our workers, and this distress will increase 
 as the available supplies are used up. Colonel H. A. Foster 
 recently pointed out, before the Bradford Chamber of Commerce, 
 that although the value of the dyes imported might not exceed 
 2,000,000 to 3,000,000 per annum, yet taking textiles alone 
 it involves indirectly a turn-over of about .100,000,000. If we 
 take into account some of the other uses which I have mentioned, 
 this enormous sum must be greatly exceeded. 
 
 The British colour makers are increasing their output, but 
 since before the war they were supplying only about 1 5 per cent. 
 of the amount used in the United Kingdom, it is obvious that 
 
THE INDUSTRY IN THIS COUNTRY 311 
 
 they will not be in a position for a long time to meet the demand. 
 Furthermore, the Germans manufactured very large quantities of 
 dyes which have never been made here. 
 
 What, then, is to be done ? I notice that the Bradford 
 Chamber of Commerce unanimously passed a resolution on 
 2 yth October "urging upon His Majesty's Government the 
 vital necessity for immediately adopting measures for furnishing 
 such support as is essential to the establishing and effectual con- 
 tinuance of the manufacture of aniline dyes upon an adequate 
 scale in this country." 
 
 To my mind, the most important part of the resolution is 
 contained in the words " and effectual continuance of the manu- 
 facture of aniline dyes." If the industry is founded, it is the 
 bounden duty of the Government to see that it is not stifled 
 again at the end of the war. 
 
 Capitalists who might be willing to risk their money in putting 
 up colour works say : But what is to happen after the war ? 
 The Germans will again flood the market and undercut. In all 
 probability they have accumulated supplies and will be willing to 
 get rid of them at almost any price. Will the Government 
 guarantee that for a certain number of years all dyeing which is 
 done for Government Departments shall be dyed only with 
 British-made dyes ? If the Government agree, and the manu- 
 facturers and users of this country should compel them to agree, 
 what about other than Government users ? Will they rush back 
 to buy in the cheapest market, because it goes without saying 
 that in most cases, for some time at least, the British dyes will 
 not be so cheap as the German, owing to the enormous experience 
 the latter have behind them. On the other hand, in our gas- 
 works we have a great deal of the raw product necessary. 
 
 My own feeling is that a large portion of the raw products 
 should be made by some of our large gas-works, that is to say, 
 those which have tar-distilling plants. They have there, in their 
 works, the benzol, toluol, naphthalene, anthracene, etc. With 
 regard to the last-named substance anthracene the British 
 Alizarin Company can probably deal with it better than anyone 
 else, but they will require increased supplies. 
 
 Why should not nitrobenzene, aniline, nitrotoluene, toluidine, 
 the naphthols, naphthylamines, phthalic anhydride, and many 
 other substances, which are the raw materials for the colour 
 works, be made at the source of supply of the raw products for 
 
312 THE BRITISH COAL-TAR INDUSTRY 
 
 their manufacture ? About 10,000,000 gallons of benzene are 
 produced annually, and before the war two-thirds of this went to 
 Germany, a portion of which they used for making aniline. 
 
 The question is one bristling with difficulties, but it is of 
 instant urgency. Some suggest the establishment of huge works 
 comparable to those of the Badische or Meister, Lucius & 
 BrUning (forgetting that those were built up from comparatively 
 small beginnings), which will manufacture every type of colour 
 and also fine chemicals, a scheme which would mean in the long 
 run a huge financial disaster. Others think that a number of 
 small firms should be founded which would manufacture certain 
 specific ranges of colours. This certainly is more feasible. 
 
 My own feeling is that those firms now manufacturing should 
 enlarge their output and obtain leave to work certain German 
 patents ; that many of the raw products should be manufactured 
 at one or two of the great gas-works who might, after their plant 
 was working, also make certain dyes and gradually branch out ; 
 also that a few new companies with carefully thought-out pro- 
 grammes should be started. 
 
 Now in connection with the protection of the industry I wish 
 to say another word. We will presume that the Government 
 will only allow the use of British-made dyes. How about the 
 other consumers ? It will be very difficult to bind them. The 
 best solution of the problem would be to give them, or rather 
 get them to take, an interest in the new works, or, for a matter 
 of that, in the old ones. This was done by the Turkey Red 
 Dyers' Association, who, in order to prevent the manufacture of 
 alizarin leaving the country, founded the British Alizarin Com- 
 pany, and agreed to take so much of the output. They were 
 thus not dependent upon the Germans, and also had an interest 
 in the manufacture of the product. Cannot the general dyers do 
 something similar ? 
 
 In conclusion, I wish to say just one word as to the revocation 
 of German patents. After war was declared, the Home Office 
 revoked all German and Austrian patents, as and during the 
 continuance of the war. It was also stated that in certain cases 
 licences would be granted to British manufacturers to take up 
 and work these patents. I was informed recently by an eminent 
 patent lawyer and by one of the largest patent agents in London, 
 that the granting of licences is practically a dead letter. Further, 
 that where licences have been granted, a royalty is reserved for 
 
THE INDUSTRY IN THIS COUNTRY 313 
 
 the enemy, and there is no certainty that those who have obtained 
 a licence during the war will be allowed to work the patent after 
 the declaration of peace. 
 
 If the trade is to come to this country, and to be retained by 
 it, it is of vital importance that these matters be cleared up, and 
 the Government must help. 
 
 DISCUSSION 
 
 The Chairman (Mr E. HICKSON) said many people seemed to 
 think that the colour trade in Germany had been fostered and 
 helped by the Government in a manner which was quite out of 
 proportion with the truth, and those of them who had seen the 
 little jubilee books recently issued by some of the German firms 
 who had celebrated their fiftieth anniversary would know quite 
 well how true was the lecturer's statement that most of these 
 firms started on the most insignificant scale. 
 
 The Lord Mayor of Leeds (Mr J. E. BEDFORD) said it was 
 particularly interesting to hear the early history of this subject 
 from the lips of one who bore the honoured name of Perkin. 
 He thought it was their duty to recognise the scientific and 
 business-like manner in which Germany had conducted and 
 developed this important industry. When the present crisis 
 developed, the Government had very promptly set up at the 
 Board of Trade a Chemical Products Committee, and called 
 together eminent business and scientific men to discuss the 
 matter, and see how the stoppage of the textile and printing 
 industries could be avoided. Some of them had taken the view 
 that it would be absolutely necessary, in order to build up and 
 foster this industry, for the Government to give some form of 
 protection. He himself had suggested at a meeting of the Leeds 
 Chamber of Commerce that we should have to put a protective 
 duty of about 25 to 30 per cent, on imported aniline dyes, and 
 his friends had reproached him with the fact that he was a 
 Liberal Free-trader, and was now turning Conservative. He 
 had replied : " 1 am still a Free-trader, but in extraordinary 
 circumstances and in time of war you must adopt war methods.'' 
 He believed they had in England a sufficient number of highly 
 trained chemists to develop the industry. He was sure that 
 there were certain of the simple colours which could be tackled 
 at once if the requisite amount of capital were available. 
 
3 14 THE BRITISH COAL-TAR INDUSTRY 
 
 Professor W. M. GARDNER said one point which appeared to 
 him worthy of mention, and which was not included in the list 
 of reasons given for the loss of the industry, was perhaps a 
 fundamental one. Dr Perkin had to some extent touched upon 
 it when he mentioned that in the development of the synthesis 
 of indigo upwards of 1,000,000 had been spent in experiment 
 before any return was obtained. It appeared to him that this 
 would have been quite impossible in England, because the 
 investing public would never have supported an expenditure of 
 any such sum. Want of knowledge and of interest on the part 
 of the investing public had been one not unimportant cause why 
 companies had not been formed for the development of the 
 industry in this country. There were other reasons why it was 
 peculiarly difficult to regain the industry, and here again he 
 should like to touch upon a point which the lecturer, no doubt 
 from lack of time, did not mention ; and that was the important 
 way in which secondary and subsidiary interests had been built 
 round the great coal-tar colour industry of Germany, such as 
 the manufacture of synthetic medicines and synthetic scents and 
 flavourings on the one hand, and the manufacture of necessary 
 reagents, such as fuming sulphuric acid, on the other. These 
 had put the industry in Germany in an extremely strong position, 
 since before we could hope successfully to compete with them 
 we should have to launch out, not only in the manufacture of 
 colours, but in many other directions, so that altogether an 
 enormous outlay of capital would be required. The public must 
 recognise that it was a most complicated question, and one which 
 would require not only great enterprise and co-operation on 
 the part of manufacturers and consumers, but would inevitably 
 require assistance from the Government. 
 
 The Lecturer said the subject was so big that he was afraid of 
 digressing on side issues, but he quite agreed with Professor 
 Gardner that one of the reasons why the industry had become so 
 great in Germany was the working up of by-products. What 
 was waste in one product was the starting-point in making 
 another product, and if they were going to manufacture 
 successfully in this country they must pay attention to that fact. 
 It was no use saying they would manufacture this or that dye 
 and neglect all its by-products. If they did, the cost of the dye 
 would be out of all proportion to its cost as it was manufactured 
 abroad. 
 
XXIV.: 1914 
 
 THE SUPPLY OF CHEMICALS TO BRITAIN 
 AND HER DEPENDENCIES 
 
 BY SIR WILLIAM A. TILDEN, D.Sc., LL.D., F.R.S. 
 
 (Journal of the Royal Society of Arts^ 2Jth November 1914, p. 26) 
 
 To those who can look back over half a century, the progress 
 of scientific and industrial chemistry, and the relations of the one 
 to the other, present many features of extreme interest. After 
 the days of Lavoisier, and during the earlier part of the nineteenth 
 century, the foundations of theoretical chemistry were laid by the 
 efforts, contemporaneous but independent, of the chemists of 
 England, France, and Sweden. The great names -associated 
 with the movement include Davy, Faraday, Dalton, Gay-Lussac, 
 Dumas, and Berzelius. There were no German chemists of the 
 first rank in those days, and if we look among them for funda- 
 mental discoveries we can only find one of considerable import- 
 ance, namely, the discovery of isomorphism by Eilhard Mitscher- 
 lich in 1819. But the birth of Justus Liebig at Darmstadt, in 
 1803, gave to German science a leader whose influence stretches 
 down to our own day, and is felt wherever chemistry is studied or 
 practised. The department of organic chemistry has been the field 
 in which the most remarkable successes have been won, though 
 not wholly, as sometimes represented, by the German chemist. 
 
 The relation of optical activity to atomic constitution was the 
 discovery of le Bel, a Frenchman, almost simultaneously with 
 van 't Hoff, a Dutchman, and the application of their theories 
 to the phenomena presented by compounds other than those of 
 carbon was illustrated in the first instance by Smiles, and by Pope 
 and Peachey, all of whom are Englishmen. It will also be only 
 fair to state that while we readily acknowledge with admiration 
 the brilliant work of von Baeyer and Emil Fischer in connection 
 
 315 
 
3 i6 THE BRITISH COAL-TAR INDUSTRY 
 
 with the synthesis of indigo, the sugars and the proteins, the 
 fundamental principles which underly all chemical theory have 
 been established almost entirely by the chemists of other nations. 
 It is only necessary to recall such subjects as the atomic theory, 
 the periodic law, Faraday's laws of electrolysis, the theory of free 
 ions, the phenomena of radio-activity, and the discovery of radium, 
 to show that in laying down broad general principles German 
 chemists have not usually been the first in the field, though at 
 later stages they have shown great and commendable activity. 
 
 Turning now to the position of industrial chemistry, a single 
 brief quotation from the " Report on Chemical and Pharmaceutical 
 Products and Processes" in the International Exhibition of 1862, 
 from the pen of A. W. Hofmann, then Professor of Chemistry 
 in the Royal College of Chemistry and Royal School of Mines, 
 London, will be sufficient. He says (p. 3) : " The contributions 
 of the United Kingdom, and in particular the splendid chemical 
 display in the eastern annexe, prove the British not only to have 
 maintained their pre-eminence among the chemical manufacturers 
 of the world, but to have outdone their own admitted superiority 
 on the corresponding occasion of 1851." 
 
 On referring to the table of statistics which appears on the 
 same page of the report, we find that of the 762 exhibitors in 
 the class, the United Kingdom was represented by 200, while 
 Germany, Austria, the Zollverein, and the Hanse towns together 
 mustered only 136. France stood next with 115 exhibitors. It 
 will be remembered that at the date of the exhibition the dis- 
 covery of the so-called aniline colours was bearing very important 
 industrial fruit. Mauve, or aniline purple, was discovered by 
 W. H. Perkin in 1856, and aniline red was first obtained 
 industrially by Verguin and Renard Freres of Lyons a few 
 years later. 
 
 It is also interesting to notice that among the early investi- 
 gators and patentees of processes connected with the production 
 of colour from coal-tar hydrocarbons, only English and French 
 names are to be found, with the significant exceptions of Hofmann 
 and Caro, both of whom were at that period resident in England. 
 At this time synthetical chemistry in the modern sense was as yet 
 unpractised because unknown. Such an important substance as 
 salicylic acid, for example, was a mere laboratory product, obtain- 
 able only from natural sources. 
 
 But the activity of the chemical industries in the United 
 
THE SUPPLY OF CHEMICALS TO BRITAIN 317 
 
 Kingdom is not to be measured only by reference to subjects 
 such as those of the coal-tar colours, nor by the number of 
 exhibitors in an international exhibition even at that early period 
 in the history of exhibitions, at which manufacturers were far 
 more eager to find a place than they have been in more recent 
 times. Statistics in relation to the development of the alkali 
 trade show how rapidly the production of what are called " heavy 
 chemicals " was proceeding at this period. Figures derived from 
 returns collected by Mr Christian Allhusen from 8 1 per cent, of 
 the manufacturers in the United Kingdom, immediately after the 
 first Great Exhibition, are shown below. These may be compared 
 with statistics prepared by Mr W. Gossage for the year 1861, 
 immediately before the Exhibition of I862 1 : 
 
 
 1852. 
 
 1861. 
 
 
 Tons. 
 
 Tons. 
 
 Soda ash .... 
 
 71,193 
 
 156,000 
 
 Soda crystals .... 
 
 61,044 
 
 104,000 
 
 Bicarbonate .... 
 
 5>762 
 
 13,000 
 
 Bleaching powder . 
 
 13,100 
 
 20,000 
 
 The value of these products for 1852 was estimated at about 
 ij million pounds, while the value of the products of 1861 was 
 calculated by Mr Gossage at upwards of two millions sterling. 
 
 The Board of Trade has recently issued a Bulletin concerning 
 German competition in the United Kingdom market, and on 
 page 2 we find the statement that the soda compounds, excluding 
 chromates and bleaching powder, produced in the United 
 Kingdom in the year 1907, are valued at 3,390,000. The im- 
 ports from Germany in 1912 are valued at only 8700. As 
 to bleaching materials, the product of the United Kingdom for 
 1907 is estimated at 527,000, while the import from Germany 
 for 1912 was 44,600. 
 
 From these figures the easy deduction is made that "the 
 imports of these chemicals into the United Kingdom from 
 Germany are relatively insignificant when compared with the 
 output of the same articles in this country. It is clear that in 
 these particular lines British manufacturers have no need to 
 fear German competition in the home market." 
 
 1 Gossage's History of the Soda Manufacture. 
 
318 THE BRITISH COAL-TAR INDUSTRY 
 
 Similar remarks apply to aluminous compounds, coal-tar 
 products not dyes, the cyanides, sulphuric acid, and other acids 
 for which the Bulletin may be consulted. It thus appears that 
 the British manufacturers of sulphuric acid and soda, from the 
 early times of a century ago, have been able, up to the present, 
 to hold their own against foreign competition, and have thus 
 added substantially to the revenues and well-being of their 
 country. 
 
 The immense advances in every direction made in all 
 civilised countries have brought demands in steadily increasing 
 quantities for a variety of materials of which many were unknown 
 to the generations immediately preceding our own. These are 
 almost all the outcome of the progress in our own time of 
 chemical knowledge. Since the introduction of the coal-tar 
 dyes the development of chemical theory has rendered possible 
 the production in the laboratory of a large number of organic 
 substances which are either identical with compounds already 
 known as occurring in Nature, or from their ascertained physio- 
 logical action' have added incalculably to the resources of the 
 physician and surgeon in relieving pain and in curing disease. 
 These include not only drugs for internal administration, but 
 antiseptics, the use of which was only beginning to be recognised 
 at the time of the Exhibition in 1862 (Hofmann's Report, 
 pp. 104-105). 
 
 To these must be added essential oils and other volatile 
 aromatic substances, the application of which to perfumery and 
 flavouring has undergone a stupendous development during the 
 last thirty years. 
 
 The innumerable applications of photography have also 
 led to a deniand for developing, fixing, and toning materials, as 
 well as for plates and films on a very large scale. 
 
 The arts of peace as well as the operations of war have also 
 led to the production of explosives of many new types formerly 
 unknown. 
 
 There is also another department of business which requires 
 notice, and that is the demand for pure chemical reagents for 
 analysis and research, which has increased to an extent very 
 difficult to calculate, but is manifestly very large. The modern 
 university and technical colleges, nearly the whole of which have 
 come into existence within the last forty years, the large body 
 of Public Analysts appointed under the Sale of Food and Drugs 
 
THE SUPPLY OF CHEMICALS TO BRITAIN 319 
 
 Act, 1875, the establishment in nearly all the public schools and 
 high schools of laboratories for teaching chemistry, as well as 
 the numerous technical laboratories connected with such in- 
 stitutions as the Government Laboratory, the National Physical 
 Laboratory, the Metropolitan Water Board, and many others, 
 afford sufficient evidence that there are several hundreds of 
 chemical laboratories distributed over the United Kingdom in 
 which pure chemicals are required for analytical purposes. 
 
 Now, leaving to the department of " heavy chemicals " all 
 such things as agricultural and horticultural washes, coarse disin- 
 fectants and artificial manures, the question arises : How do 
 we in England stand in regard to the supply of drugs, dyes, 
 photographic chemicals, and perfumes at a time when many of 
 these things are very urgently needed ? 
 
 It may be safely asserted that the sources of supply of all 
 these materials in the United Kingdom are seriously inadequate. 
 And, further, we may point to the acknowledged fact that many 
 of the dyes, and nearly all the synthetic drugs and photographic 
 materials have been systematically imported from Germany. 
 
 The Annual Statement of the Board of Trade (p. 108) shows 
 that in 1913 we imported from Germany : 
 
 
 
 Alizarin and anthracene dyes . . . . 271,119 
 Aniline and naphthalene dyes . . . 1,382,478 
 Synthetic indigo 76,681 
 
 1,730,278 
 
 Under the head of " Drugs, unenumerated, including 
 Medicinal Preparations " (p. 107), out of a total of imports from 
 foreign countries and from British possessions amounting to 
 1,302,860, more than one-fourth, or to the value of 332,464, 
 was in 1913 received from Germany. From this is to be 
 deducted the inconsiderable amount of dyes and other chemicals 
 from coal-tar, valued at 24,691, exported in 1913 to Germany 
 (p. 300). According to the Final Report on the First Census of 
 Production of the United Kingdom for 1907 (p. 547), this 
 country made 139,000 cwt. of coal-tar dyes, valued at 373,000, 
 of which practically the whole was consumed at home. 
 
 As to fine chemicals for analysis and for research, there are 
 no figures available, but it may safely be said that there has been 
 no appreciable production of these things in this country. If 
 
320 THE BRITISH COAL-TAR INDUSTRY 
 
 such a statement is met by protests from manufacturers who pro- 
 fess to supply these materials it is only necessary to refer to 
 the experience of analysts and directors of research laboratories, 
 which has compelled many of them to resort habitually to 
 German makers for their supplies of trustworthy reagents. 
 
 If we are ever to be in a position to supply ourselves and 
 our dependencies with the dyes, the drugs, and the rest of the 
 fine chemicals required in our work, it will only be achieved after 
 a careful review of the circumstances which led to the removal 
 of the industries from this, the country in which many of them 
 originated, together with a determination to take to heart the 
 lessons of the past. 
 
 A chemical manufacturer, discussing the neglect of fine 
 chemicals in this country, recently made the remark : " What 
 does it matter, if we are making money ? " I venture to say 
 that that view expresses neither patriotism nor common sense. 
 For the same principles which have served as the basis of the 
 German success in relation to dyes and fine chemicals apply 
 equally to the production of heavy chemicals, and already 
 German chemists have been boasting that, having secured the 
 trade in the former, they are about to attack the latter. 
 
 The export trade in sulphuric acid alone is already three 
 times as great from Germany (1912) as from the United Kingdom 
 (1913), as shown by the figures given in the recent Bulletin 
 issued by the Board of Trade (Commercial Intelligence Branch, 
 October 1914). 
 
 The recent success of Professor Haber, of Karlsruhe, in 
 the synthetical production of ammonia from hydrogen and 
 atmospheric nitrogen, a process which has been put into opera- 
 tion on an industrial scale by the Badische Company, ought 
 surely to carry something significant to the unprejudiced mind. 
 Neither is it superfluous to point to the extensions taking place 
 in several countries of operations in which the nitrogen of the 
 atmosphere is being fixed in the form 4 of cyanamide, of nitrites 
 and nitrates in which the industrial lead has been taken by 
 Germany, which also supplies a large proportion of the capital, 
 though at present not to the exclusion of the British. 
 
 The extent to which the German chemist arrogates to himself 
 the whole field of scientific and industrial chemistry is illustrated 
 in the report (given in full of Nature, Ixxxv. p. 558) of a lecture 
 given by Professor Emil Fischer on nth January 1911, in the 
 
THE SUPPLY OF CHEMICALS TO BRITAIN 321 
 
 presence of the Emperor, on the occasion of the inauguration of 
 the Kaiser Wilhelm Gesellschaft zur Fflrderung der Wissen- 
 schaften. It is at least unpleasant to hear of a man so eminent 
 as Professor Fischer, and so worthy of respect, treating the 
 subjects of his discourse as though every one of them had 
 originated and been developed in Germany. Perkin is indeed 
 referred to as the discoverer of mauve, but every other foreign 
 name is omitted. 
 
 If I now try to recall some of the circumstances which led 
 to the gradual transference of the colour industry from this 
 country to Germany, and the failure to establish here any 
 appreciable production of the synthetical drugs and other 
 chemicals now so urgently needed, it will not be the first time 
 the facts have been stated and the obvious conclusions deduced 
 therefrom. 
 
 All the substances referred to belong to the department of 
 organic chemistry, and it might perhaps be supposed that neglect 
 of this branch of the science by the chemists of this country was 
 the cause of the loss of business. When Hofmann was un- 
 fortunately allowed to leave the College of Chemistry to return 
 to his own country, a check was for some time observable in the 
 output of research among us, but it must be remembered that 
 the number of institutions in all countries in which the study 
 of chemistry was pursued was then relatively small. Even in 
 Germany the Chemical Society in Berlin did not come into 
 existence till 1867, anc ^ U P to tnat time th ere had been no 
 laboratory for practical instruction in chemistry in the university 
 of that city. 
 
 For the last thirty years, however, the progress of research 
 in this country has gone forward at an increasing rate, though 
 still less rapidly than in Germany. The slow development of 
 chemical teaching and research in this country was attributed 
 by many people to the anti-scientific influences at work in our 
 universities, and especially the older universities. This point 
 of view was exposed very clearly and forcibly by the late Sir 
 William Perkin in presidential addresses delivered to the 
 Chemical Society and the Society of Chemical Industry in 1885 
 (see p. 75, ante). And up to this time it would be indeed difficult 
 to exonerate Oxford and Cambridge from responsibility in the 
 evil example shown by those great seats of learning. But since 
 that day many changes have taken place, and great advances 
 
 21 
 
3*2 THE BRITISH COAL-TAR INDUSTRY 
 
 have been made. What is wanted in the British universities 
 is, first of all, that no man shall in future be appointed to a 
 professorship, or indeed to any teaching post in connection with 
 physical or natural science, who does not show his ability to 
 instruct in the higher branches of his subject by the character 
 of the researches which he continues to carry out during his 
 tenure of office ; and, secondly, such a change in the curriculum 
 and endowments that there may be not only a supply of 
 instruments and materials but a sufficient body of trained 
 assistants in the form of advanced students to enable the 
 professor to pursue without delay any promising line of 
 investigation. 
 
 Notwithstanding the difficulties which stand in the way the 
 scientific chemists of this country are, however, not idle. 
 Evidence of this may be seen in the Transactions of the Chemical 
 Society , the volume of which for 1913 contains 238 papers 
 extending over more than 2300 pages. And when it is 
 remembered that these papers have survived the severe 
 censorship exercised by the Publication Committee of the 
 Society the result must be considered encouraging. It appears, 
 then, that it is not to the scientific part of the chemical world 
 that blame attaches in recent times. 
 
 Forty years ago it would be safe to say that there were 
 
 practically no chemists engaged in the direction of the chemical 
 
 works or this country, and by chemists I mean fully qualified 
 
 scientific men. Probably in the palmy days of colour-making it 
 
 would have been difficult to meet with a British manufacturer 
 
 who had ever heard of Kekule's benzene theory, or would have 
 
 thought it worthy of a moment's notice by a practical man. 
 
 And yet at the Kekule Jubilee in 1890 a representative of the 
 
 German coal-tar colour industry declared that the prosperity of 
 
 Germany in this direction was primarily due to this theoretical 
 
 conception. Even in much later times the chemical manufacturer 
 
 in this country has repeatedly had facts laid before him which 
 
 ought to have attracted his serious attention. One of the most 
 
 convincing statements was laid before this Society by Professor 
 
 Meldola on I3th May 1886 (see p. 121, ante\ and one would 
 
 suppose that the figures then given would have been sufficient 
 
 to create well-founded alarm. For he showed, on the testimony 
 
 of a considerable number of prominent English dyers, that 
 
 already about nine-tenths of the colours employed by them were 
 
THE SUPPLY OF CHEMICALS TO BRITAIN 323 
 
 imported from Germany. Again, in a lecture given before the 
 British Association in 1901, on the "Relative Progress of the 
 Coal-tar Industry in England and Germany during the Past 
 Fifteen Years " (see p. 189, ante). Professor Green showed clearly 
 the steady increase in the imports of dyestuffs from Germany 
 into England, and the steady decline in the production of similar 
 materials in England. 
 
 Finally, we have the fact known to all the world that one 
 of the most notable triumphs of German chemical industry is 
 the production of synthetic indigo made from naphthalene on 
 a scale so large as to have almost driven the Indian planter from 
 the field. In this case we have over again a story nearly 
 corresponding to the history of the introduction of artificial 
 alizarin in 1869, an event which was speedily followed by the 
 abandonment of the cultivation of madder in the south of 
 France and elsewhere. And to-day we learn from the Board 
 of Trade Statement for 1913 that we imported indigo from 
 Germany to the value of ^76,681, while the value of the 
 natural indigo from India has declined from ^124,1 12 in 1909 
 to ^48,208 in 1913. As to the cause of this serious reduction 
 of chemical business authorities are unanimous. 
 
 Perkin, in the address to the Chemical Society already quoted, 
 attributed the success of the German industries to the employ- 
 ment of high-class chemists (Trans. Chem. Soc., xlv. [1884], 
 p. 219 et seq.}. 
 
 The same view was expressed by Professor Meldola in his 
 paper before this Society in 1886. "The strength of our 
 competitors," he says, " is in their laboratories and not, as here, 
 on the exchanges." 
 
 Professor Green stated as his opinion, in the lecture referred 
 to, that the remedy for the present state of affairs can only be 
 found in a better appreciation of the value of science throughout 
 the length and breadth of the land, and that it is not so much 
 the education of our chemists which is at fault as the scientific 
 education of the public as a whole. Nor can much improvement 
 be expected till the public, including manufacturers, can be 
 disabused of the fallacy that a year or two of technical training 
 pumped into an ignorant schoolboy will produce a better works 
 chemist than a university course of scientific study laid upon the 
 foundation of a good general education. 
 
 If these are supposed to be merely the prejudiced opinions 
 
3 2 4 
 
 THE BRITISH COAL-TAR INDUSTRY 
 
 of British chemists, the sentiments expressed by German manu- 
 facturers themselves may be appealed to. 
 
 In 1900 a lecture was delivered on the occasion of the 
 opening of the Hofmann House in Berlin by Dr H. Brunck, 
 since 1884 chief technical director of the Badische Company, on 
 the "History of the Development of the Manufacture of Indigo " 
 (see p. 204, ante). This lecture, in the form of the English 
 version issued by Dr Brunck, may be fairly regarded as a sermon 
 preached to British manufacturers. Its perusal will convince 
 anyone that the success which has been achieved is the reward 
 of long-sustained investigation in the laboratory of the scientific 
 chemist, and to do justice to this conviction I wish every chemical 
 employer in this country could be induced to read the weighty 
 and eloquent words of the author. He would then perceive 
 that to permanent industrial success there is only one road, and 
 that the way pointed by science. 
 
 I will content myself with quoting only a passage or two 
 from Brunck's lecture : 
 
 " With grateful admiration and reverence do we recall those 
 ever memorable masters, Kekul6 and A. W. von Hofmann, 
 whose gifted achievements have laid the foundations of our 
 industry. And when we look back at all the technical achieve- 
 ments we also gratefully recall the fertile discoveries of Graebe 
 and Liebermann, of Peter Griess, and the beautiful researches 
 of Emil and Otto Fischer, of O. N. Witt, and the numerous 
 other investigations conducted in our university laboratories, 
 which have acted as incentives for chemical industry, and have 
 furnished the foundation for renewed progress. But first and 
 foremost we are impressed by the mighty influence of the 
 investigations of A. von Baeyer, to whom the coal-tar colour 
 industry is indebted for a great number of important achieve- 
 ments, and who himself has, to-day, unfurled before you the 
 picture of a magnificent scientific creation, from which it was 
 possible for chemical industry to construct and develop one of 
 its grandest achievements. 
 
 " But this infant industry was no longer content to be 
 dependent on the gifts which were made to it from various 
 scientific sources. Renowned investigators placed themselves 
 entirely at the disposal of chemical industry ; young men in 
 great numbers devoted themselves to it, and grew up with it 
 in enthusiastic and self-directed activity. Such men as Caro, 
 
THE SUPPLY OF CHEMICALS TO BRITAIN 325 
 
 Glaser, Martius, and later on Laubenheimer, Duisberg, Bernthsen, 
 and many others, introduced the spirit of scientific investigation 
 into industrial practice." And, in conclusion, he says : " You 
 have seen that this new industry is not an unexpected gift fallen 
 from the heavens, but that in order to complete the task the 
 intellectual labour and the industry of many men had to be 
 co-ordinated in an organised attempt to attain a definite object 
 for a number of years and throughout a considerable period 
 when success could by no means be regarded as certain. The 
 pre-requisites for practical indigo synthesis were supplied by the 
 results of long years of scientific labour." 
 
 In the semi-annual report for April 1903 issued by 
 Schimmel & Co., the famous manufacturers of essential oils, 
 there are some figures which show the increase of chemical 
 works in Germany and the great increase in the numbers of 
 qualified workmen employed therein, on which the firm makes 
 the following remark : " The foregoing figures show clearly 
 that the German chemical industry has passed intact through the 
 economic crisis of the last few years. Further, there are no 
 grounds for fearing that it will be outstripped by competition 
 from abroad, so long as the German universities possess such 
 eminent representatives of chemical science." 
 
 It is now time to consider what ought to be done and what 
 it is possible to do in this country to remove reproach from 
 British chemical industry, and to render the Empire independent 
 of supplies from foreign sources. 
 
 We need many first-rate chemists, a few engineers, plenty of 
 capital, and some good men of business. A combination of these 
 elements in due proportion is certain of success, and the time, 
 though so unhappy for the world, is favourable for this enterprise. 
 
 Inasmuch as the functions of each and the best way of com- 
 bining them have already been settled in practice on the Continent, 
 it is to be hoped that the ancient precept about being taught by 
 the enemy -fas est et eb hoste doceri will not be forgotten. For 
 there can be no doubt that the principle acted on in all German 
 chemical factories, namely, the employment of the best available 
 scientific skill and the constant appeal to scientific research, has 
 been the secret of their success. 
 
 In the British colleges and universities there are many able 
 young chemists, but many more are required. Here education 
 and industry interact on each other. If the demand for scientific 
 
326 THE BRITISH COAL-TAR INDUSTRY 
 
 assistance were more general, the supply of well-qualified men 
 would soon be greatly increased, and greater attention given by 
 the teachers to the industrial side of the subject. At present 
 other professions in which the prospects are more alluring attract 
 into other lines of work much of the talent of the country. 
 This, however, is not to be interpreted as meaning that there is 
 not now a supply of able young chemists sufficient for immediate 
 needs. The difficulty is to induce chemical manufacturers to 
 treat them reasonably. The pay offered is generally insufficient, 
 and though conditions are somewhat improved of late years, the 
 employer too often expects immediate profitable returns from the 
 engagement of a scientific man. In the Badische works at 
 Ludwigshafen the plan has been to engage university men on 
 the recommendation of their professors for a term of years, at a 
 salary which will enable the new members of the staff to live at 
 least modestly. I am told that in some American works the same 
 system has been adopted. These young men are placed in the 
 research laboratory under the chief chemist controlling the de- 
 partment of manufacture selected, and it is not expected that they 
 will accomplish anything very remunerative at first. But their 
 future depends on their ability and activity, and they act 
 accordingly. 
 
 Then there is the position to be accorded to the engineer. 
 He is, of course, indispensable ; but the part he should play in 
 the works depends on the nature of the processes involved. So 
 far as relates to buildings and other structures, to supplies of 
 water, fuel, power, and electricty, the engineer has the field to 
 himself, but the operations in which materials are to be employed 
 in producing and controlling chemical reactions which lead to the 
 desired product belong to the chemist, and here he ought to be 
 supreme. In some of the old-established operations an engineer 
 with an elementary knowledge of chemistry may carry on fo a 
 time, but in these days a chemist with the most extensive and 
 intimate knowledge of physical chemistry is necessary if these 
 processes are to continue to be profitable. As to the production 
 of dyes and other organic synthetical products, the operations 
 involved are in many cases so nearly similar to laboratory pro- 
 cesses that the chemist requires very little assistance from the 
 engineer. 
 
 As to capital, it is necessary to remember that it will have to 
 be provided liberally. A single fact mentioned in Brunck's 
 
THE SUPPLY OF CHEMICALS TO BRITAIN 327 
 
 lecture on indigo, given already fourteen years ago, shows the 
 spirit in which the German manufacturers attacked the problem 
 of the industrial production of this one colouring matter. They 
 had then invested about 900,000 for this purpose. 
 
 The works of the Badische Anilin- u. Soda-Fabrik at Ludwigs- 
 hafen are arranged on a plan, which clearly recognises the in- 
 separability of research and manufacture. A number of rect- 
 angular buildings, four storeys high, are so arranged that the 
 railway lines may traverse the works in two directions at right 
 angles to each other. Each building is devoted to the production 
 of one substance or closely allied group of substances. The top 
 floor is occupied by the laboratory of the chief chemist attached 
 to that department, with several assistants. Below is found an 
 intermediate floor where processes previously tested in the 
 laboratory, or suggested as the result of research, may be tried 
 on a scale sufficiently large to determine their practicability before 
 being transferred to the lower floors where the actual manufacture 
 is conducted. I doubt if anything so complete or so commercially 
 successful exists elsewhere in the world. 
 
 How many chemical manufacturers among us can boast 
 that they regard science in a light so serious as to have pro- 
 vided in their works a properly equipped laboratory with a com- 
 petent staff whose occupation is not confined to the analytical 
 testing of materials or products, but extends to the systematic 
 endeavour to introduce improvements into old methods or the 
 discovery of new ones ? A few such enlightened firms do exist, 
 but the figures quoted show how much mischief has already 
 been done. 
 
 A variety of other questions have recently been raised in view 
 of the circumstances which have been forced on our notice by the 
 war. There is not time for the discussion of the state of the law 
 as to patents, but a couple of sentences in Schimmers report for 
 April 1908 show that "great alarm has been caused in the whole- 
 sale chemical industry of Germany by the new British Patent 
 Act, which came into force on ist January 1908, according to 
 which every patent may be declared void if it is exclusively 
 exercised abroad without sufficient grounds. Many firms are 
 thereby compelled to transfer a part of their production to the 
 United Kingdom, a fact which, in the interests of many thousands 
 of German workmen, is sincerely to be regretted. " 
 
 With regard to duty-free alcohol, I am informed, on the best 
 
328 THE BRITISH COAL-TAR INDUSTRY 
 
 authority, that the regulations in this country are now compar- 
 able with those of the German Government, and that there is 
 very little ground for complaint. In the vast majority of cases 
 suitably denatured alcohol can be employed without loss or 
 inconvenience. 
 
 There has been a good deal of discussion on the subject of 
 trade-marks and proprietary names, much of which I regard as 
 futile. With regard to drugs, there should be no great difficulty 
 in instructing the medical profession in those comparatively few 
 cases in which the names are changed. 
 
 In conclusion, two remarks only require to be made. The 
 establishment of what will be practically a new industry in this 
 country will require consideration and assistance from the State, 
 if it is to survive the period of fierce competition which will 
 follow the conclusion of the war. Encouragement is already 
 promised to the dye industry, in the form of definite financial 
 aid to be given by Government. But remembering that the 
 colour-maker is dependent on the production of many chemi- 
 cals, which represent intermediate stages in the processes which 
 lead from the raw materials to the finished product, and that the 
 production of these chemicals is naturally associated with other 
 chemical manufactures, it is to be hoped that the temporary 
 production will be extended beyond the immediate field of the 
 colour-maker. 
 
 The other remark may raise a smile on the part of those 
 business men who are moved only by commercial considerations. 
 There will be a great temptation when the war is over to resume 
 former business relations with the enemy. The German chemical 
 manufacturers have a powerful organisation and many years of 
 experience behind them. Let them keep any markets they can 
 retain outside the British Empire, but every man who cares for 
 his country will surely demand that business at home shall be 
 limited to British goods. 
 
 DISCUSSION 
 
 The Chairman (Sir WILLIAM RAMSAY), in opening the dis- 
 cussion, said the paper emphasised what we had been told so 
 often during past years, that too little attention had been paid 
 to the scientific side of chemical manufacture in Great Britain. 
 But there were two aspects of the question which had not, he 
 
THE SUPPLY OF CHEMICALS TO BRITAIN 329 
 
 thought, been sufficiently touched on. The first aspect was as 
 follows : Trade was regarded in Germany as a war ; all means 
 of conquest were looked on as permissible. At the annual 
 meeting of the Society of Chemical Industry in 1903, he had 
 said : " It was the Prussians who first showed how a modern 
 army should be organised . . . they have at Berlin a council 
 which arranges each particular of each possible campaign ; the 
 men are known who will take the command, and from rank to 
 rank the knowledge is spread as to what particular part each 
 officer and each man will have to play in the campaign. The 
 matter is not left to chance. . . . An exactly similar policy is 
 being pursued by Germany in the matter of industry. It would 
 be curious if it had not occurred to the persons who are respons- 
 ible for the military organisation of Prussia that a similar policy 
 is applicable to commerce. It would be remarkable if, having 
 succeeded so well in their military organisation, no attempt had 
 been made to establish a similar commercial organisation ; and 
 we shall not go wrong if we assume that there is a council whose 
 proceedings are kept quiet but which takes into consideration the 
 statistics obtainable, and as far as possible legislates, or endeavours 
 to legislate, on the basis of these statistics. Where fiscal duties 
 are found to be wanted, such a council puts them on ; where 
 there is an advantage in taking them off, they take them off. 
 Where cheap transit is possible, they let it be given ; for the 
 railways are the property of the State. Is it to be expected that 
 any country can fight such a combination as that without adopt- 
 ing, at all events, something of their methods, or without study- 
 ing their methods, and without combining together, if not to 
 imitate them, at all events to thwart them ? " He had put the 
 second aspect of the case in a leader in Nature ', on i2th Novem- 
 ber 1914. He would quote it. Dealing with the organisation 
 of a German chemical business, he pointed out : " First, the 
 management consists, not in a board of well-meaning elderly 
 gentlemen with a works-manager in their employment, but in a 
 board of specialists, whose business in life is to manage the factory 
 financially, chemically, and as engineers, and who are very highly 
 paid for their services. Second, these gentlemen and a special staff 
 are continuously on the look-out for any scientific discovery or 
 invention which can prove of advantage to their business. Third, 
 a very large staff of men, trained in universities or technical 
 schools, is turned on to the problem of making such a discovery 
 
330 THE BRITISH COAL-TAR INDUSTRY 
 
 commercial, whether by securing cheap raw material, cheapening 
 the process of manufacture, or creating a public demand for the 
 article to be manufactured. Fourth, a legal staff is maintained, 
 whose business it is to protect by patent all improvements, 
 however apparently trivial, and to describe them so vaguely as 
 to conceal them from their competitors ; these gentlemen, in 
 some cases, have also to advise whether piracy is likely to be 
 successful : whether it may not be possible, by infringing a 
 patent, so to saddle an opponent with legal expenses as to break 
 his competition. Fifth, such companies are so powerful that 
 they can influence the central Government to protect all new 
 developments, whether by imposing duties on articles which 
 might possibly compete, by extending bounties to exported 
 products, or by securing advantages in freights to the coast, and 
 in shipping the goods abroad. Sixth, agencies are maintained all 
 over the world whereby the article is introduced to the notice of 
 foreign purchasers ; and last, an extensive credit system is 
 encouraged." German competition was thoroughly organised 
 and systematic ; their plan had been to attack some material 
 manufactured here, and, by one of the means alluded to, to render 
 its manufacture unprofitable. Having obtained a monopoly, prices 
 were raised. That was a not unusual method of commercial 
 warfare ; but it was only in Germany that all the resources of 
 the State were combined to render it easy. How were such 
 tactics to be met ? First of all, there must be co-operation and 
 trust among our chemical manufacturers. They had to be taught 
 to fight, not each for his own hand, but against a common enemy. 
 Smaller works, which had not funds to maintain an expensive 
 research staff, must combine to obtain efficient laboratories. The 
 products of one works must supplement those of another, and 
 the manufacturers must be organised. Second, competition which 
 was unfavourable, owing to fiscal regulations or patent laws, must 
 be combated by the action of the State, after advice and careful 
 consideration, so that our manufactures and trade might not 
 be unfairly attacked by duties, by export bounties, or by easy 
 freights. 
 
 Professor JAMES J. DOBBIE thought it might confidently be 
 said, with regard to the supply of trained chemists, that at present 
 this country was in a better position than ever it had been before. 
 In the smallest of the Scottish universities, owing in the first 
 place to the munificence of a former professor, and more recently 
 
\ 
 
 THE SUPPLY OF CHEMICALS TO BRITAIN 331 
 
 owing to the operation of the Carnegie benefaction, a research 
 laboratory had been founded and endowed, which was now well 
 able to hold its own with any laboratory in this country, and with 
 many of the German laboratories. At present there were no less 
 than twelve students there, all of whom were in a position to take 
 part in work to which they had been invited by a committee of 
 the Royal Society, namely, assisting in the production of certain 
 drugs which were necessary for the Army and Navy, and which 
 at present could not be had from the ordinary sources of supply. 
 He thought that was an encouraging circumstance. As to the 
 capital, no one would doubt that that would be forthcoming if it 
 were to be employed for the particular purposes of developing 
 the chemical industries which had hitherto been in the hands of 
 the Germans. But there remained the further point : Were the 
 chemical manufacturers themselves ready to employ the scientific 
 assistance which was needed, and were they ready to remunerate it 
 adequately ? Unless they recognised the necessity for the em- 
 ployment of the highest science in the development of their 
 industries very little progress could be made. It was to the 
 education of the masters of the industry that attention had to be 
 devoted. He was glad the author had called attention to the 
 fact that this country had contributed some of the great funda- 
 mental principles to chemistry. There was no want of originality 
 in this country ; there was no want of initiative ; where we had 
 got behind was simply in the power of organisation, or rather the 
 failure to organise. 
 
 Mr A. E. BERRY said that manufacturers had not always 
 received the assistance and help which, in his opinion, should 
 have been afforded to them. A few days ago one of the com- 
 panies in which he was interested received an inquiry for a certain 
 product that had always been made in Germany. That product 
 required pure duty-free spirit. His company wrote to the Inland 
 Revenue, saying they had accepted the business and must have 
 duty-free spirit. That day he had received a visit from an officer 
 of that department, who had spent an hour and a half arguing 
 that the product must be made by something else than duty-free 
 spirit. He claimed that manufacturers in this country had the 
 knowledge and scientific ability to manufacture such a product, 
 but were debarred from doing so by the Government restrictions 
 with regard to duty-free spirit. 
 
 Professor A. G. GREEN remarked that the question, as the 
 
332 THE BRITISH COAL-TAR INDUSTRY 
 
 author stated, was simply one of knowledge. The Germans had 
 considered it was worth their while to pay in order to obtain 
 knowledge ; we had not, and until we had changed our methods 
 we should still continue in the same old way. An instance had 
 come under his notice a few days previously which showed the 
 manner in which we were accustomed to proceed in this country. 
 A certain firm in the North of England, of very considerable 
 standing, had their attention directed to a certain substance, and 
 were advised it would be a very profitable thing to take up. 
 Instead of making inquiries as to where they would obtain the 
 best scientific skill and advice as to the manufacture of it, or 
 instead of engaging a chemist, they advertised for a workman who 
 had made the product. They succeeded in getting a workman, 
 and the man then immediately said he must have a certain raw 
 material. It was not to be obtained. Then they had to consider 
 the question of manufacturing the raw material. They then 
 proceeded to advertise for another workman with a knowledge 
 of its manufacture. He (the speaker) did not know the sequel, 
 but he thought it was pretty clear what it would be. Sir William 
 Tilden considered there were no difficulties with regard to indus- 
 trial alcohol at the present time. He (the speaker) was of that 
 opinion until a month or two ago, but from inquiries he had 
 made he was no longer of that opinion. The law as it stood 
 would, he thought, if interpreted in a liberal manner, suffice to 
 give all that was required, but as the law was now interpreted it 
 did not. For instance, the price of ether in England was nearly 
 three times as much as it was in Germany. That simply excluded 
 the manufacture in England of a large number of materials in 
 which ether was required. The Excise authorities absolutely 
 refused to allow ether to be made from pure alcohol ; it had to 
 be made from industrial alcohol. That put a large extra cost on 
 the manufacture of ether from several points of view. Acetic 
 ether was another product which was debarred from being made 
 from pure alcohol, because the Revenue people considered it 
 would be possible to regenerate alcohol from the acetic ether ! 
 Ether was the starting-point of the manufacture of quite a 
 number of fast yellow dyestuffs, which it was impossible to make 
 in this country owing to the fact he had just stated. But he did 
 not mean to say that the alcohol question was one of premier 
 importance. The question of the employment of chemists came 
 first. The British manufacturer must employ a larger number 
 
THE SUPPLY OF CHEMICALS TO BRITAIN 333 
 
 of chemists, and he must reward those chemists sufficiently to 
 make it worth their while to do their utmost. 
 
 Mr A. CHASTON CHAPMAN said that there was a very large 
 body of British manufacturers who imagined that the office was 
 the central and most important part of their works, and that all 
 they had to do was, that if they paid their chemists (if they 
 employed scientific assistance at all) 100 per annum, to ensure 
 that at the end of the year there was 150 in their till. It 
 seemed to him that not only that section of the British manu- 
 facturers had to be educated, but also the British public, who in 
 such matters were exceedingly ignorant ; and it was through the 
 British public that pressure could be brought to bear on the 
 authorities where pressure was very badly needed. 
 
 Mr WALTER F. REID remarked that he did not grudge the 
 Germans the slightest bit of profit they made out of their own 
 inventions, but when an invention was made in this country and 
 it had to go abroad to be worked, there was something radically 
 wrong in the way the British inventor was treated. He could 
 give dozens of instances where inventors had produced good 
 ideas, but, owing to lack of help and opportunity, had had to let 
 their ideas die or sell them for a mere song. That was not a 
 healthy state of things. He might mention that he invented 
 smokeless powder. In the first place he had taken it to a 
 Government factory, and explained its properties. Some time 
 after an official waited upon him and said that all he claimed for 
 the powder had been proved, but that it could not be introduced 
 into the Army because, if it was, all the rifles would have to be 
 altered ! 
 
 The Government should assist inventors. British manu- 
 facturers were in the position of an untrained mob going against 
 a drilled army. The commercial aspect of the matter was, in his 
 opinion, of the greatest importance, but the author in his paper 
 had put the business man last. He (the speaker) ventured to 
 suggest that some of the largest and best industries in the 
 country had been developed in the first instance by good men 
 of business. 
 
 Colonel CHARLES E. CASSAL (President of the Institution of 
 Chemical Technologists) said plenty of trained scientific chemists 
 were certainly necessary, but it was forgotten that in order to 
 produce the trained scientific chemist a long period of technical 
 education was necessary, which put a very severe tax upon the 
 
334 THE BRITISH COAL-TAR INDUSTRY 
 
 father of the young chemist. After that, he had to be offered 
 something which was worth his while, and which would attract 
 the right sort of man. Many manufacturers in this country 
 had followed the objectionable practice of appointing Germans 
 as their chemists in preference to Englishmen, because the 
 former were " cheaper." He hoped that an end would be put 
 to this. 
 
XXV.: 1914 
 
 BRITAIN AND GERMANY IN RELATION TO 
 THE CHEMICAL TRADE 
 
 BY WILLIAM R. ORMANDY, D.Sc., F.C.A. 
 
 (Journal of the Royal Society of Arts^ 4th December 1914, p. 46) 
 
 THE fact that Germany has slowly but surely been gaining 
 control of the greater part of the chemical industries of the 
 world has been brought home to this country times innumerable 
 during the last forty years. It is true that this control has not 
 extended to the manufacture of what are known as heavy 
 chemicals, where questions as to the cost of raw materials, fuel, 
 and freight are of deciding importance. The present unhappy 
 state of Europe, causing a shortage of many drugs and chemicals, 
 has brought this control home in an unmistakable way to the 
 public, who have been made to realise what the manufacturers 
 have known and ignored for at least a generation. 
 
 It is probable that the laws relating to the influence of en- 
 vironment, which have been proved to be so important in the 
 animal and vegetable world, will be equally applicable to the 
 development of industries, save that influences, such as national 
 temperament, education, and financial relations of a complex 
 nature, have to be brought into consideration. Industrial 
 development on a very large scale was first rendered possible 
 by the introduction of the steam-engine as a power generator 
 and the provision of adequate means of transport. At a period 
 during which this development was taking place here, the rest 
 of Europe was in a sufficiently unsettled state to permit of this 
 country, without serious opposition, becoming the workshop of 
 the world. No finesse was required to sell the output of our 
 mills and our ironworks. America, like a healthy growing child, 
 
 335 
 
336 THE BRITISH COAL-TAR INDUSTRY 
 
 had an inconceivable appetite for all those finished and inter- 
 mediate products which could only be produced by a nation 
 whose industries had been slowly developed and well established. 
 In those days the English manufacturers, who paid low wages 
 and exacted long hours, made enormous profits. The experi- 
 menting which had to be done to develop the various industries 
 was of a rule-of-thumb character and essentially non-scientific 
 in its nature. Probably no nation is so well fitted as the Anglo- 
 Saxon race to develop rapidly along such lines. As a race our 
 people are practically inclined, and so long as development 
 required nothing more than the close application of a healthy 
 common sense, progress was astonishingly rapid. A very old 
 man, whose family was one of the earliest to take up the manu- 
 facture of cast steel in this country, has told me that in the 
 early days of the firm's history it was no uncommon thing to 
 receive orders for tons of steel required for the manufacture of 
 drills and tools to open up the virgin wealth of America, in 
 which not only was no price mentioned, but it was explicitly 
 stated that within the bounds of reason quick delivery would 
 compensate for any price. The products of our boiler yards 
 were famed throughout the world, and incredible profits were 
 made by firms whose successors have found the competition of 
 recent years more than they could support. This was, of course, 
 due to the fact that in the days of prosperity the profits were 
 divided to the last penny, the machinery was allowed to get out 
 of date, and the working people refused any longer to play the 
 part assigned to them by the manufacturer in his profit-making 
 schemes. Dr Mollwo Perkin has probably given the correct 
 explanation for this pronounced tendency of British manu- 
 facturers to starve and bleed their own business. The rapid 
 industrial development of foreign countries called for enormous 
 capital for railways, shipping, docks, and harbours, and the 
 opening up of mining and agricultural properties, and it was 
 felt that a better return could be obtained from such ventures. 
 English spinners and weavers were supplying the whole world 
 with their products, while loom and mule machinery makers 
 were working day and night to supply these foreign purchasers 
 with the machinery for their infant industries which were in future 
 years to compete with the home country for their own and 
 neutral markets. For close upon a hundred years the tide flowed 
 in our favour. There was no necessity to practise economy. 
 
CHEMICAL TRADE IN BRITAIN AND GERMANY 337 
 
 Nature had been lavish with our raw materials, our insular 
 position and the proximity of our manufacturing centres to the 
 sea-board gave us natural advantages which, added to a favour- 
 able situation in international relations, rendered the growth of 
 our material success inevitable. To the thinking mind, it was 
 obvious that such a concatenation of favourable circumstances 
 could not continue indefinitely. We provided other countries, 
 at great profit to ourselves, with all the means necessary for 
 competing with us in these markets in which we had hitherto 
 enjoyed a practical monopoly. Our own works were frequently 
 equipped with out-of-date machinery, which was busily employed 
 in making more modern plant which was put into the hands of 
 those who realised that they would have to exert their powers 
 to the utmost if they were to gain a fair share in the barter of 
 the great international bazaar. The British industry of to-day 
 is in the position of a son inheriting an established business, and 
 having in addition a very large income derived from the labours 
 of past generations. Properly used, such a situation should 
 make for enhanced prosperity ; but even such powerful ad- 
 vantages may be nullified if the effort to work along the lines 
 which proved successful in our grandfathers' days be continued 
 too long. Capital directed by ignorance and apathy cannot hope 
 to compete for ever against the forces which are brought to bear 
 to-day. 
 
 The industrial life of Germany may be said to have com- 
 menced little more than a generation ago. To all intents and 
 purposes an inland country, with little sea-board, they were 
 under a huge disadvantage in every department which required 
 raw materials obtained from abroad. In many directions their 
 natural resources were comparatively poor. They had no iron 
 ores which were comparable with the hematites of Cumberland, 
 their limestone was largely dolomitic, their coals were for the 
 most part poor in quality, and lay often in distorted seams, more 
 like those of our Bristol coalfields than the comparatively easily 
 worked deposits in our northern area. It was recognised at an 
 early period in their industrial development that national progress 
 in a country situated as was their own could not be left entirely 
 to individualistic effort. Nationalisation of railways and canals 
 became an obvious necessity if differential traffic rates were to 
 be allowed, and differential rates were an absolute necessity if 
 large industries were to be developed in the interior of Germany 
 
 22 
 
338 THE BRITISH COAL-TAR INDUSTRY 
 
 far from the sea-board. Too much credit cannot be given to 
 the far-sighted way in which every problem of agriculture and 
 industry in Germany is regarded from a national standpoint. 
 It is realised by everyone that individuality must be, to a' certain 
 extent, fettered for the benefit of the nation as a whole. In this 
 country individuality runs rampant, and except in times of stress, 
 such as those through which we are passing, the national or 
 Imperial bearing of any individualistic action receives not the 
 slightest consideration. The very people whose fathers sold 
 land to the railway companies at absurdly inflated prices now 
 complain that, owing to the high railway freights in this country, 
 they cannot make adequate profits from the investment of the 
 money obtained from those same companies by an earlier ex- 
 tortion. No doubt many of those who have made their profits 
 from such action would like to see the English railways 
 nationalised and freights reduced at the expense of that patient 
 beast of burden, the British public. Whereas Germany is con- 
 tinuously developing her network of waterways, we in this 
 country, with a customary lack of national forethought, allowed 
 our waterways to become controlled by the railway companies. 
 
 Having thus settled the enormously important question of 
 transport, Germany had to consider the lines along which she 
 should seek for an expression of her industrial destiny. 
 Agriculture, there as here the largest individual industry, 
 received attention which is as striking as is the lack of it in this 
 country. Proper afforestation schemes were rendered compulsory ; 
 enormous areas of land fit for little else were put under potato 
 cultivation, and science was called in to help to create a new 
 outlet for the crops. Germany became essentially the starch-, 
 glucose-, and alcohol-producing country of Europe. Other 
 large areas were used for the cultivation of the beet, and once 
 again science was called in to assist in the disposal of the roots 
 as raw materials for the production of sugar. If the manu- 
 facturing of iron had to become a great industry, it was necessary 
 to develop economic methods for the utilisation of the great 
 deposits of low-grade phosphatic iron ores which were those 
 chiefly available. In addition to the home deposits of iron ore 
 large amounts have been imported, but how successfully the 
 problem has been tackled is shown when we consider that 
 twenty years ago the German production of iron was a mere 
 fraction of our own, whereas to-day the German output exceeds 
 
CHEMICAL TRADE IN BRITAIN AND GERMANY 339 
 
 the British by nearly 100 per cent. The problem of working 
 up the complex metallic ores has fallen almost entirely into 
 German hands. They alone were willing to spend the time 
 and money necessary on researches pertaining thereto, and they 
 alone seemed willing to devote that close chemical skill and 
 attention which is necessary in dealing with these complex 
 problems. In the early days of the chemical industry it must 
 have been quite evident that Germany could not hope to compete 
 in those branches of heavy chemicals such as soda ash, caustic 
 soda, sulphuric acid, bichromate of soda, alum, etc., where cheap 
 raw materials, freights, and cheap fuel play a greater r61e than 
 chemical skill and complex machinery. There is, however, not 
 the slightest doubt that Germany realised years ago what this 
 country has not yet grasped namely, that all industrial develop- 
 ment tends to become more and more scientific. The adequate 
 utilisation of the by-products from an industry may settle the 
 question of the survival of the industry itself. 
 
 The necessity for broad co-operation in great industrial 
 problems was recognised and acted upon in Germany in a 
 hundred directions. By-product recovery coke ovens were 
 installed in the immediate neighbourhood of the blast furnaces, 
 and the surplus gas from both was used for power generation. 
 The steelworks were erected in the immediate vicinity of the 
 blast furnaces, so that the surplus power might have an economic 
 outlet. Where it was impossible to bring the steelworks to the 
 vicinity of the coke ovens and the blast furnaces, the surplus 
 energy from these was transmitted far and wide in the form 
 of high-tension electric current sold at an astonishingly low 
 price and thus tempting to the introduction of new small 
 industries within the immediate area. The by-product recovery 
 coke ovens were required to another end. Slowly but surely 
 Germany had been developing her fine chemical industries, 
 drugs, and dyes. Many of these manufactures were dependent 
 for their raw materials on products only obtainable in quantity 
 from this country. We have been building up an enormous 
 industry, not only in the spinning and weaving of cotton and 
 woollen yarns and fabrics, but a correspondingly great industry 
 in the bleaching, dyeing, and finishing of these products. This 
 has been chiefly developed on dyes obtained from Germany, 
 but while we have been content to leave ourselves entirely in 
 the hands of others, the Germans have, by the exercise of 
 
340 THE BRITISH COAL-TAR INDUSTRY 
 
 scientific skill and a sensible use of capital, rendered themselves 
 independent of this country. German capital was spent like 
 water to foster the development of by-product coke ovens and 
 in the development of the allied fireclay trade for the production 
 of suitable apparatus, to the end that fifteen years ago practically 
 the whole of the hard coke produced in that country was made 
 to give up its toll of by-products which were the raw materials 
 for their great chemical industry. 
 
 At a recent meeting of the Society of Chemical Industry, 
 Professor Henderson referred to the chemical industries of 
 Germany as being merely the development of the crumbs from 
 the British loaf with which they had had to content themselves. 
 In so far as the metallurgical industries are of necessity chemical 
 industries, the term " crumb," as applied to an iron and steel 
 trade much greater than our own, seems out of place, and the 
 remark is only another unfortunate example of the willingness 
 that exists in many quarters to pander to an already too strongly 
 developed feeling of national self-esteem. The British as a 
 nation never show up so favourably as when they are placed face 
 to face with difficulty. As a race we have so much of which we 
 can be genuinely proud that it is a little less than treason when 
 those to whom the people should look for guidance and warning 
 feed them with fulsome flattery and lull them to continued sleep 
 with mental opiates. In ever-increasing degree, both in this 
 country and Germany, the population are dependent on in- 
 dustries for their livelihood. Both countries have long passed 
 the stage at which their home market is capable of keeping the 
 industrial machine in full activity. In addition to each being the 
 other's largest customer, both have to look to the rest of the de- 
 veloped parts of the world for an additional outlet. Someone has 
 said that a nation gets the newspapers it deserves. Judging by 
 what has appeared in some portions of the daily Press during 
 recent months upon the subject of German trade, it is devoutly to 
 be hoped that the common sense of the British nation will not be 
 judged thereby. During the past ten years a nation of over sixty 
 millions has been increasingly occupied in industrial operations. 
 Our own smaller population has, on the whole, been equally 
 fully employed during the same period, and yet people write 
 as though there was a possibility that a large proportion of the 
 activities of the larger nation could be profitably undertaken in 
 the smaller country whose work-people have been for the most 
 
CHEMICAL TRADE IN BRITAIN AND GERMANY 341 
 
 part well and profitably employed for the last decade. The 
 absurdity of this requires no refutation. Indignation is expressed 
 at the discovery that German people and German capital are by 
 way of controlling an ever-growing number of industries in this 
 country. I have not seen that any serious attempt has been 
 made to the much more serious end of discovering why the 
 Germans should desire or should be able to get such a foothold 
 in this country. In some few instances I could supply an 
 answer from my own experience. We have already seen how 
 the German Government brings science and agriculture to work 
 together in afforestation, and the cultivation and utilisation of 
 potatoes and beetroots, but throughout the German national 
 history the Government has recognised that, as a people, they 
 are in ever-growing degree forced to live on industry, and that 
 modern industry is built on the hand-in-hand co-operation of 
 science and capital. This country is dependent upon industrial 
 development for its very existence in a higher degree than 
 Germany, and yet so far as governmental assistance or interest 
 is concerned the principal occupation of the British people might 
 be the signing of dividend coupons. The German Government 
 is incomparably poorer than our own, and yet the financial 
 assistance which it renders to technical education is immeasur- 
 ably greater. The standard of general education is undoubtedly 
 higher, no doubt largely in consequence of the temptation 
 offered by their one-year service system in the army to those 
 who have passed a certain high standard of efficiency. In a 
 land where the standard of payments is, on the whole, much 
 lower than our own, the leading men of German technical schools 
 are far better paid than in this country. The heads of the 
 technical school staffs are encouraged to become acquainted with 
 the latest technical progress. It is fully realised that a purely 
 academic teacher cannot turn out first-class technical men. The 
 technical industries instantly claim, at higher salary, the members 
 of the staff of technical colleges who have carried out original 
 investigations which seem likely to open out industrial possi- 
 bilities, and it is not an uncommon thing for such a man to be 
 reclaimed by some technical institution at a later date at a still 
 higher salary. It is realised that the right man, who has works 
 experience as well as technical knowledge, is worth far more 
 to the nation as a teacher than in a private capacity. If an 
 industry requires to make use of ingredients such as alcohol and 
 
342 THE BRITISH COAL-TAR INDUSTRY 
 
 ether, which are under excise control, the Government will go to 
 the greatest trouble to arrange matters in such wise that no needless 
 restraint is imposed. That the staff of a Government department 
 should interpret a Government order in an unduly restrictive 
 sense, so that an industry might thereby be hampered, is there 
 inconceivable. Only in Great Britain and Turkey are Govern- 
 ment restrictions allowed to be interpreted at the will of the 
 permanent officials. I do not for one moment wish to imply 
 that I consider that the question of industrial alcohol has been 
 of the main, or even of serious, import, compared with others, 
 in our neglect of the fine chemical industries. I quote it rather 
 as an example of the contemptuous attitude which our Govern- 
 ment has hitherto adopted towards matters industrial. In certain 
 branches of the chemical trade it is essential to have the 
 chemically pure alcohols and ethers, but the would-be manu- 
 facturer is told, by the Government, in effect, that he is not to 
 be a judge of what is necessary, but that the question will be 
 settled by some heaven-sent genius in their permanent employ 
 who, like the journalist on a halfpenny paper, knows more about 
 the subject than the man who has made it a life's-work. 
 
 A feature of the German industries is their willingness and 
 ability to work in co-operation, as is shown in many ways which 
 are no doubt familiar to most of you, but with which we have 
 not time to deal. With all the help which a favourably-inclined 
 government could render, the German industries would have 
 been unable to approach their present standard of efficiency had 
 it not been for the remarkable co-operation which takes place 
 between science and capital. This can perhaps be best illustrated 
 by means of some concrete examples. Let us suppose that some 
 chemist in Germany has discovered a new and cheaper method 
 for making some chemical product which is in considerable de- 
 mand, or which might become a large article of manufacture if 
 the price were sufficiently low. If the manufacture is likely to 
 require a considerable capital, the inventor would probably go to 
 one of the large banks. The German banks permanently retain 
 the services of some of the leading authorities on a wide range of 
 subjects, and the inventor would be asked to put all his case before 
 the particular expert in charge of his department. If the report 
 were of a sufficiently satisfactory nature on the scientific side, the 
 bank would proceed to make their own inquiries, through the 
 many channels open to them, as to the probable outlet for the 
 
CHEMICAL TRADE IN BRITAIN AND GERMANY 343 
 
 new product. If the outlook were in all respects sufficiently 
 satisfactory, they would advance the necessary capital at a reason- 
 able rate of interest, making certain stipulations such as that the 
 business should be carried through their bank ; that payment for 
 the finished products should be made through the bank ; that no 
 contract for the sale of the finished product should be made with 
 any firm without their consent. The bank having much greater 
 facilities for gauging the financial standing of the purchasing 
 public, in this wise protect their own interests and that of the 
 inventor. 
 
 Again, nothing is more startling to the Englishman than the 
 ease with which one can gain admission to those in command of 
 the great industries. The directors of the German companies, 
 for the most part, and the managing director invariably, are men 
 of high technical skill in the business they control. The idea of 
 putting a stockbroker or a retired army colonel at the head of a 
 scientific industrial concern would be regarded as an act of mad- 
 ness. Not only are German businesses run by men who under- 
 stand them, but these industrial leaders have always time to give 
 adequate consideration to any new proposal which is brought 
 before them. It would be the exception rather than the rule to 
 find directors in an English company who were capable of ap- 
 preciating, still less of judging, the merit of a technical point 
 relating to their own business. It would be almost an impossi- 
 bility for an unknown outsider to obtain admission to such 
 directors, and even if the unknown inventor succeeded in getting 
 within the veil which hides the holy of holies, it would probably 
 be to find that the master-mind had so many appointments that 
 he never by any chance had time enough to consider any proposal 
 thoroughly. The heads of a German concern have always time 
 to look thoroughly into anything which interests them ; they are 
 sufficiently technical to realise the necessity for going into details, 
 a works experience having taught them that it is on details that 
 great processes come to grief. In spite of their intellectual and 
 commercial attainments, however, these directors are, in some 
 respects, both modest and unassuming. They still think that 
 success can be purchased only at the cost of labour ; they are 
 content to work from 8.30 to 6.30, with two hours' pause in the 
 middle of the day, and they work full six days to the week. No 
 doubt they envy, but they do not lay claim to, that super-type of 
 intellect which, labouring hard from eleven till four with an in- 
 
344 THE BRITISH COAL-TAR INDUSTRY 
 
 terval for rest, sometimes even five days a week, expects, not only 
 to retain its old position, but to dispossess its competitors ; they 
 even learn foreign languages so that they may profit by the 
 knowledge gained by other people in other countries. 
 
 Let us suppose for one moment that it was Germany that 
 was short of drugs, photographic chemicals and dyes, and that 
 England had possessed a monopoly in these products. Further, 
 we will suppose that the joint general manager and head chemist 
 of one of the large English drug and photographic chemical 
 works had found himself in Germany at this period, with 
 sufficient acquaintances in that country, men with whom he 
 had for many years made large contracts and who were fully 
 cognisant of his scientific and technical ability to guarantee his 
 claims. He could go to any bank and say : " I can show you 
 how to make a number of photographic chemicals and drugs 
 even more cheaply than they can be made in the country which 
 has hitherto controlled the manufacture, because you have the 
 necessary raw materials, because you have, indeed, previously 
 sold these raw materials to the previous makers. I bring you 
 the necessary evidence that these products can be made at half 
 the sales price obtaining before the war, and I can demonstrate 
 that the sale in your own and neutral countries of these products 
 amounts to some thousands of tons per annum, and that, under 
 normal circumstances, after the war is over, it will be impossible 
 for your business to be displaced by undercutting. Finally, I 
 will bring you reputable dealers who will make contracts for 
 hundreds of tons of these products at prices which will pay for 
 the plant and show profits in one year's working." The bank 
 would confirm these statements through their experts, and probably 
 within forty-eight hours all the money that was required would 
 be available at yj per cent. The man who possessed the scientific, 
 technical, and commercial knowledge would thus be enabled to 
 build up a business which would be profitable to himself and 
 valuable to the community, the fact being that it is recog- 
 nised in Germany that capital is entitled to a fair return and 
 nothing more. 
 
 Now let us imagine that circumstances were reversed. It 
 would require the pencil of a Hassall adequately to depict the 
 scene in the board-room of an English bank where such a 
 proposal had been made. One can imagine the possessor of 
 such knowledge offering it to existing chemical works. 
 
CHEMICAL TRADE IN BRITAIN AND GERMANY 345 
 
 Modern commerce is warfare, and the weapons employed are 
 inventions, tireless industry, skill, and capital. We make the 
 mistake of putting the last first. Those who do research and 
 make inventions, whether in chemistry, engineering, or any other 
 branch, are the yeast which leaven the whole mass, but in this 
 country we do not allow those conditions of warmth which permit 
 the yeast to work. Gold in itself is not nearly so valuable a 
 metal as iron, and we are slowly but surely finding out that 
 capital itself is an over-valued possession if it be not used for 
 the benefit of the industries and consequently of the nation as 
 a whole. 
 
 DISCUSSION 
 
 The Right Hon. Lord-Justice MOULTON said that he had 
 had allotted to him for several weeks past the business of in- 
 vestigating into the question of the supplies of articles which in 
 peace time were imported from Germany. First and foremost 
 of those had been the problem of the great chemical trades, 
 especially the great industry in synthetic dyes, and he had had 
 an opportunity of marking in detail those things in which England 
 had allowed herself to be supplied in chemicals from Germany. 
 He could assure the audience that he had noted the fact with 
 great sadness, and, he was bound to say, it was a great national 
 humiliation. The fact was that chemistry opened up, especially 
 some fifty years ago, a domain of industrial wealth which he 
 could only compare to the domain which was opened up when 
 steam power was first invented ; and to his great sorrow he 
 could come to no conclusion but one, and that was, that either 
 from being too well off, or from sluggishness of intellect, or from 
 the fact that the capital of the country had passed into the hands 
 of people who were unwilling either to learn or to think, England 
 had abstained almost entirely from attempting to reap the rich 
 harvest that was opened to the industrial world by the advances 
 in organic chemistry. The fact was too well marked for us to 
 pass it by as being a mere incident in national life. Of course, 
 no one thought that every nation could do everything ; and that 
 nations should, to a certain extent, specialise, should take ad- 
 vantage of their natural position, and the deposits that they 
 found in their land, their climate, and things of that kind, was 
 not only normal but desirable. But thought depended on no 
 climate. Thought was open to us all ; and the fact that England 
 
346 THE BRITISH COAL-TAR INDUSTRY 
 
 neglected the chemical industries could not be explained away 
 by any suggestion that it was either incapable or for any natural 
 reason unfitted for their pursuit. One had to look deeper than 
 that. One had to find some fault either in the national character 
 or in the national behaviour which would account for it ; and he 
 did not believe that England could, after the war, survive as a 
 great industrial nation if she did not correct that fault, if she 
 did not make an effort to take her place and that an uppermost 
 place in the world of industry in chemical matters as well as 
 in all others. If the conclusion was come to that it had been 
 by a national fault that we had missed it in the past, and that 
 we were not going to live a disgraced life in future, it meant 
 that that fault must be found out for the purpose of avoiding 
 it, and there, he thought, a lesson might be taken from our 
 enemies. To his mind by far the most glorious moment in 
 the history of Prussia was not the moments of her military 
 successes it was the moment of her deepest disaster. Those 
 who knew Prussian history would remember that after the 
 nation had been prostrated by Napoleon in the Battle of Jena 
 the national independence was utterly taken away. The restric- 
 tions the conqueror put upon them were humiliating in every 
 way. At that time there arose a set of men, of whom he chose 
 to name, first, Fichte, who told the Prussian people in the 
 clearest language that their disaster was due to their national 
 faults, and pointed out the way that they must correct these ; and 
 in the most unsparing language he told them that it was only by 
 self-discipline, only by taking to heart their disaster, seeing in it 
 the natural consequence of their national faults, that they could 
 possibly get the resolution or the strength to replace their nation 
 in the position which it ought to occupy. The whole nation 
 listened. It was at that time that the Germans took to physical 
 development and voluntary drilling. They prepared themselves 
 in every possible way for that coming fight which they hoped 
 they would have with their oppressors, and which they had in 
 the course of a very few years, but they did it under the exhorta- 
 tions of these men, because they did not attempt to hide from 
 themselves that it was the nation that was to blame for its 
 misfortunes. 
 
 The fact that our chemical industries were in such a backward 
 state, with certain exceptions of those which needed least thought 
 and least study and least knowledge, was grave enough, if, as 
 
CHEMICAL TRADE IN BRITAIN AND GERMANY 347 
 
 he said, it was due to our national faults it was grave enough 
 for us in these days to rouse ourselves as the Prussians did rather 
 more than one hundred years ago. He was quite sure that if 
 we did do it the same result would come that we should regain 
 our position, and regain it with even more glory than it possessed 
 before. There was a time when in no industry could England 
 look on other nations as its superior. Now, in the chemical 
 industry by which he meant mainly the organic chemical industry 
 it was all but insignificant, and he read with very bitter feelings 
 an address of one of the ablest industrial chemists in the world, 
 the head of the German chemical industry, who was talking about 
 the very subject, and who said : " England talks now of not only 
 holding her own in war, but beating us in our chemical industries. 
 She cannot do it, and that is because the nation is incapable of 
 the moral effort to take up an industry like that which implies 
 study, which implies concentration, which implies patience, which 
 implies fixing one's eye on the distant consequences and not 
 considering merely the momentary profit." When he read those 
 words he asked himself, Was that not a fair judgment for a 
 foreigner who could not know the resources of the English 
 people in the way of repentance and resolution and reformation ? 
 Was it not fair for that gentleman to say that our behaviour 
 during all these years showed that we were incapable of doing 
 it ? And he would tell them frankly, that if we did not take the 
 lesson to heart at the time of this war, and when the war had 
 passed when, as we believed, we should have severed ourselves 
 from the military domination of Germany resolve to save our- 
 selves from industrial domination, all he could say was that the 
 victory of Germany, if not in the form that it would desire, 
 would be quite as great as it could wish. 
 
 Sir WILLIAM A. TILDEN said he had listened with mixed feel- 
 ings not only to the paper but to Lord Moulton's remarks. He 
 could not help hoping most sincerely that the words which had 
 been used by Lord Moulton would find an echo in those regions 
 inhabited by the leaders of British industry ; for it appeared to 
 him that unless a good many of them first of all were brought 
 to acknowledge their position of humiliation, and secondly, de- 
 termined that if they were too old themselves to learn, at any 
 rate their sons and successors should be taught what was neces- 
 sary in the way of scientific instruction connected with their own 
 businesses, then it was all over with British industry. He must 
 
348 THE BRITISH COAL-TAR INDUSTRY 
 
 say out of his own experience, living as he had for fourteen years 
 in a great industrial centre, that many of the author's pungent 
 remarks were really not exaggerated. He used to see, with great 
 regret, young men driving to business in the morning at eleven 
 o'clock when the works had been going from six o'clock. In 
 many works which he had visited he invariably was amazed at the 
 extraordinary ignorance displayed on the part of the partners them- 
 selves in the operations which they were supposed to conduct in 
 their businesses. Over and over again he had been in works in 
 the Black Country, and his friend, the director or manager, was 
 exceedingly anxious to show him anything ; but if he asked any 
 question about details the manager or director could not answer 
 them, but sent down the yard for " Old Tom " or " Old George," 
 who was the only person in the place who seemed to know how 
 the process could be conducted. He did not believe that the 
 serious character of the question of education had yet been com- 
 pletely realised by the present industrial directors and leaders, 
 and he could not help thinking that that was one of the most 
 important considerations to be taken into account at the present 
 time that the young men who were to be the manufacturers of 
 the future should have a very different kind of career from that 
 which had been hitherto prevalent. 
 
 Dr M. O. FORSTER said, whilst fully agreeing with the author 
 in his castigations of the manufacturer and the Government, 
 yet he did think that while chemists were so busy in casting 
 motes from other people's eyes, there was one beam in their own 
 which certainly should be removed forthwith, and he thought 
 the present opportunity was the right occasion to remove it. 
 They had too long allowed confusion in the public mind as 
 to what really chemistry was, and what chemists did. It was 
 perfectly ridiculous that any attempt whatever should be made 
 to capture German trade while the general public had not the 
 faintest idea of the difference between the chemist and the drug- 
 gist. At the present time the only people who were entitled to 
 call themselves chemists were those who had undergone a course 
 of training at the Pharmaceutical Society or who had passed ex- 
 aminations conducted by that body. In fact, he believed, of all 
 the chemists, so-called, present that evening, only Sir William 
 Tilden was entitled to call himself a chemist by law. In Germany 
 and France chemists and druggists were clearly defined. 
 
 Dr RUDOLPH MESSEL thought that we as a nation had 
 
CHEMICAL TRADE IN BRITAIN AND GERMANY 349 
 
 been blind, so far as new chemical industries were concerned. 
 We had everything ready at our hand. At one time there was 
 a great deal of grumbling about education in science. He had 
 been in England for forty-five years, and he could well speak 
 about the enormous progress which had been made in this 
 country as far as chemistry was concerned. There was talent 
 enough, capital enough, raw material everything. But what 
 was lacking was enterprise. If the talent which was now avail- 
 able in this country was utilised, the industry would do just as 
 well here as in Germany. He had to give one word of warning 
 in establishing new industries first of all to be sure that we only 
 took up those industries which we were prepared to defend when 
 war was over. 
 
 Dr F. G. OGILVIE said that the deplorable condition to 
 which the author had drawn attention was not at all peculiar to 
 the chemical industry ; it has been observable in a great many 
 other industries. There had been a tendency in connection with 
 many individual industries for the divorce of the control of capital 
 from the knowledge and experience required to apply capital 
 effectively. It arose in the following way a man had done very 
 well, say, in the manufacture of tweeds in a centre where a large 
 tweed industry was going on. His family found themselves 
 very well to do, and were attracted, as young men, much more 
 to field sports, county meetings, and things of that sort than they 
 were to the serious study of their own particular business. The 
 net result was, when they came into power they had to work the 
 business by managers, often underpaid and undertrained, who 
 naturally, even when they proved themselves very good men, 
 had not the ready access to the application of capital year in and 
 year out which was necessary to keep the business up to date. 
 This did not happen where the sons had added scientific training 
 to practical experience in the works. In that case there were 
 good, solid, steady-going businesses which were introducing new 
 products just as fast as could be wished. 
 
 Mr ADAIR ROBERTS said that many of the businesses which 
 it was now sought to capture from Germany could be started 
 with very little capital. 
 
 Mr WALTER F. REID said he thought it was quite impossible 
 to suggest that a young chemist, just out of a college or uni- 
 versity, could get a large salary unless he showed himself to be 
 worth it. An employer would look at him as a beginner from 
 
350 THE BRITISH COAL-TAR INDUSTRY 
 
 the industrial point of view. In fact, he was an apprentice, and 
 if he was not willing to take the salary of an apprentice at the 
 beginning he could not grumble at the capitalist, who opened up 
 to him a very good future of great promise. With regard to the 
 glass industry, we had lost that industry chiefly through the 
 unwillingness of the workers in the trade to allow apprentices in 
 sufficient number. After the production of capital, the next 
 important point was the security of it. He could not put the 
 matter more clearly than it was put by the Institute of Chemistry, 
 which said, " Provided that the manufacturers could be afforded 
 some guarantee of permanency for their enterprise, and that they 
 may have some reasonable assurance that at the conclusion of the 
 war the newly developed industry will not suffer from foreign 
 competition, hitherto made possible by economic conditions 
 which do not prevail in this country." Dr Messel had said 
 exactly the same thing. If the capital which would have to be 
 invested in new and expensive plant and in the payment of re- 
 search workers and other workers could not be secured, then the 
 capitalist could not be blamed for not coming forward. Our 
 workmen and capitalists must be given the same protection as 
 Germany gave to theirs. Our German competitors could then 
 be met on equal terms, and he was not afraid in the least what 
 Englishmen would then do. 
 
 The Lecturer said he agreed absolutely with Dr Messel that 
 we must be most careful to take up only those industries where 
 we were at least on as good a footing as the Germans were with 
 regard to raw material. With reference to workmen, he had not 
 the slightest doubt that English workmen were better than any 
 other workmen on the face of the earth. But up to the present 
 neither the English workman nor the English chemist had been 
 given half a chance to handle modern scientific processes. It 
 was the opportunity to let each of them prove what he could 
 do that had been lacking. 
 
 Mr W. H. MAW said that the state of affairs which the author 
 had described as existing in the chemical industry also existed in 
 past times in many other industries. In the case of the engineer- 
 ing trades and iron and steel manufactures the last twenty years 
 had seen a very remarkable advance in the recognition of the 
 value of scientific research, and he hoped the same advance would 
 take place in the chemical industry. 
 
XXVI. : 
 
 THE MANUFACTURE OF ANILINE DYES 
 IN ENGLAND 
 
 BY THE RIGHT HON. LORD-JUSTICE MOULTON, 
 P. C., K.C., F.R.S. 
 
 (Address delivered in the Town Hall, Manchester, on 8th Dec. 1914) 
 
 SOME weeks ago now I was asked by Government to take the 
 Chairmanship of a small Committee that had to investigate the 
 straits into which England was put by being cut off from that 
 great supplying nation, Germany. I have had to investigate all 
 the unsatisfied wants that have sprung from this war, and I am 
 glad to say that in almost all the cases which cropped up so 
 numerously at first it has been found that the resources of 
 English enterprise were sufficient to meet the demand ; that 
 some makers have been more attentive to the variety of the 
 tastes of their customers ; that others have increased their works ; 
 that others have added new branches to their business ; and that 
 the straits have been alleviated if not removed. Everything that 
 has happened has placed in harsh and dissonant contrast the 
 question of dyes. Nothing that I have seen during these weeks 
 and I can claim to have spent almost every hour of the day in 
 meeting the members of the trades affected, and in trying my best 
 to find some way out of the difficulties nothing that I have seen 
 in these long weeks has weakened, nay, I can say nothing has 
 failed to strengthen, my feeling of the gravity of this problem. 
 
 The consequence is that after long reflection I have come 
 to certain conclusions, and I have not hesitated to place them 
 in the clearest language before the Government. Now the 
 Government has taken an unusual and almost unprecedented 
 step in the direction to which I refer. I am not responsible for 
 
352 THE BRITISH COAL-TAR INDUSTRY 
 
 the details of that step. I am not in any way connected with the 
 shape or form in which the action is to take place otherwise than 
 so far as it has been a necessary consequence of the advice that 
 I have given. The one thing I am responsible for is that advice, 
 and I stand here not as the representative of the Government, 
 not as an advocate of a particular scheme, but to give you the 
 same advice, based upon the same considerations, the result of 
 the same reflections. Although that is a strange position for a 
 man who is speaking in public, it is no strange position for me. 
 There are the faces of many here in the audience who in years 
 past have come to me for advice ; who have asked it and taken 
 it ; who have shown by their coming that they had faith in my 
 judgment. Well, I hope that faith has not entirely passed away. 
 
 But in any case I am coming in the attitude of one who 
 is giving advice. When I used to see them in my rooms at the 
 Temple I would as soon have thought of chanting my opinion 
 as trying to put it in eloquent words. It will be the same to- 
 day. I shall put to you in plain business language the things 
 that have haunted me for these weeks past ; things that have 
 oppressed my thoughts day and night. In my opinion we are 
 at a crisis of our national life, and I shall try to put as plainly 
 as possible, in the simplest words, the facts which have led me 
 to that conclusion. 
 
 When I began to investigate the lack of dyes I found Eng- 
 land consuming some two million pounds* worth of dyes per 
 annum. They were essential to an industry of something like 
 two hundred million pounds per annum, and on which at least 
 a million and a half workmen were dependent. And I found 
 that of the two million pounds' worth of dyes that was required 
 year by year barely one-tenth was produced within our own 
 boundaries. I looked round for industries which could at a 
 pinch supply the deficiency. So clearly demarked from other 
 industries is the great chemical industry of the coal-tar dyes that 
 1 could find no industry which could take its place. 
 
 I found that the stocks of dyes, the stocks kept in peace 
 times for no warning of the intended war had been vouchsafed 
 to English customers I found that those stocks were rapidly 
 diminishing, and that practically there was only one nation from 
 whom we could expect help. I refer to Switzerland, and I knew 
 that in that country pressure was being put by Germany of the 
 most intense kind threatening to stop all those supplies of their 
 
MANUFACTURE OF DYES IN ENGLAND 353 
 
 intermediate products on which the Swiss dyemakers had built 
 up their business, unless they would promise that not a pound 
 of their dye should, for the whole period of the war, come into 
 this country. I found certainly some English firms who were 
 manufacturing, and manufacturing successfully, in spite of the 
 competition of the Germans. But what they could supply was 
 indeed inadequate to keep going the great textile industries 
 which ultimately depend to such a large extent upon the dyeing 
 industry. 
 
 That was the serious immediate prospect. But what does 
 the future promise ? It is that which I have been brooding upon 
 ever since. Supposing that this war was finished. Supposing 
 that by the bravery of our soldiers, and by the unflinching 
 determination of our Government and that of the Governments 
 of the Allies, we come out of it politically free. What position 
 do we step into industrially ? We step into the slavery of the 
 Germans, so far as our textile and dyeing industries are concerned, 
 as absolute as they hoped to put us in a political and military 
 sense. 
 
 What I am saying is no exaggeration. In my perpetual 
 converse with those of you who are practically interested in the 
 question I have learned the German methods of carrying on 
 business. I know their way of dividing all the nations up into 
 watertight compartments, by their system of selling dyes not to 
 be exported, so that they can put the price up to one nation and 
 down to another. I know the way in which even the two great 
 rings, which may be competitors one to the other in Germany, 
 are united against the foreigner. 
 
 I say gravely, meaning every word that I say, that if peace 
 were declared at this moment you in the English textile industry 
 would be so much under the domination of the German dye- 
 producing industry that it could boycott you in the way of dyes, 
 it could overcharge you for dyes, and it could hamper that 
 industry pending the time when it had the capital and works to 
 challenge its very existence. And as an Englishman, that fills 
 me, I will not say with dismay because I have a blind faith in 
 my countrymen which makes me believe that out of the most 
 difficult position they will, when they once realise it, pull them- 
 selves successfully but it made me feel that it was my business 
 to sound a note of warning, and not let people go on thinking 
 that this trouble from shortage of dyes was one which would be 
 
 23 
 
354 THE BRITISH COAL-TAR INDUSTRY 
 
 temporary, lasting only during the war time. No. It was a 
 signal of danger which threatened us more in peace than in war, 
 and if we would not listen to this danger signal then our fate 
 was on our own heads. 
 
 Well, now, in most things you ought to consider how to do 
 them before you determine to do them. But there are ex- 
 ceptions. This war was an exception. I do not think that 
 many of us knew how we were going to struggle through this 
 war, but yet I doubt if there is a man in this audience who did 
 not feel that we must take it up. I feel about this industrial 
 war just the same. I feel that the first thing we have got to do 
 is to ,say to ourselves, " That shall not go on." And then we 
 have to set to work to find out how we can stop it. 
 
 But to find out how we can stop it we must first consider 
 what are the causes which have led to this strange position, that 
 a great enterprising industrial nation a nation which lives upon 
 export industries is in the largest of its export industries, which 
 I believe produces one-third of the total exports, at the mercy of 
 the foreigner. How was it that when the great chemical trade, 
 based on the marvellous way in which coal-tar products will 
 assume myriad forms and myriad different properties, when that 
 El Dorado was discovered, far more valuable than the Rand ever 
 will be, how was it that England did not have its share ? 
 
 Was it discovered by foreigners ? It was started by an 
 Englishman. Was it that foreigners alone had the natural 
 resources to carry it on ? For years practically all the raw 
 materials wanted for this industry were sent out in an untreated 
 state from England. Then why was it ? 
 
 Gentlemen, we have got to look the truth in the face. It 
 was for no other reason than the English dislike of study. The 
 Englishman is excellent in making the best of the means at his 
 disposal, but he is almost hopeless in one thing. He will not 
 prepare himself by intellectual work for the task that he has to 
 do. Now in the last fifty years the knowledge of the world, 
 the additions to that which we know, which have been piled up 
 from the work of ten thousand independent investigators, each 
 applying himself to one thing, have made it so that with regard 
 to each subject there is a vast amount of the " known." And a 
 wise man who means to deal with a subject will master what is 
 known before he attempts the problem of what he can do. That 
 is what the Germans, who were rightly ambitious, accepted as 
 
MANUFACTURE OF DYES IN ENGLAND 355 
 
 the condition of success in industry. If you talk to any German 
 who is engaged in any industry you will find that he knows 
 about it all that can be known. 
 
 I admit that it does not make him a more pleasant com- 
 panion. Once I found myself on the top of one of the Dolomite 
 Mountains, and the only other person there besides the guides 
 was a German. I found out that he was a chemist, and I began 
 to talk upon a chemical subject. He told me he was only an 
 organic chemist. He had not exhausted my resources, and I 
 began to talk of coal tar and pharmaceutical products. Then he 
 told me that he was a coal-tar by-product chemist. That did not 
 beat me, because I had just been righting a case of canary yellow. 
 I thought I would get some subject which was common to us, 
 and I slipped into the subject of canary yellow. Still the same 
 ominous silence for a time, and then he said, " I am only a coal- 
 tar chemist dealing with blues." But I had not finished. With 
 an Englishman's pertinacity, not believing I was beaten, I racked 
 my brains for a coal-tar blue I had had to advise on some cases 
 and I gradually, without a too obvious change of subject, 
 slipped into that. Then he finally defeated me, because he said 
 in equally solemn tones, but equally proud of the fact, " I only 
 deal with methyl blues." 
 
 That gives you an idea of the way that a German is willing 
 to give up everything so as to concentrate on the subject with 
 which he has to deal. It may limit his general view of life. I 
 confess that it is almost worse than wearing blinkers. Goggles 
 are the only thing I can think of which at all describe the mental 
 limitations. But this makes the Germans most formidable in 
 industrial questions. It makes them thorough in that which 
 they have to do. 
 
 Now, apart from certain business methods which I may have 
 to refer to later on, I believe the sole cause of England's falling 
 back, and Germany's possession of this great industry, is the 
 fact that the Germans are perfectly prepared to undertake the 
 intellectual study necessary to master the new science. The 
 English, I believe, could do it just as well, and you will find in 
 their great works English chemists as highly respected as the 
 German, and as efficient. But unfortunately the holders of 
 capital in England have had little sympathy with knowledge that 
 they did not themselves possess. As I have been talking these 
 matters over with people energetic, good, industrial producers 
 
356 THE BRITISH COAL-TAR INDUSTRY 
 
 I have always found that when I commenced to talk about the 
 intellectual study necessary to deal with chemical science there 
 has always been that tone recalling the voice of the sluggard, 
 " You waked me too soon." 
 
 They know the time is coming when they will have to do it, 
 but they hope that during their time the traditional ways of their 
 fathers may be sufficient, and let the next generation face the 
 intellectual difficulty of study. The consequence has been that 
 inventions great inventions have fallen dead in England. 
 They have been offered in Germany ; they have been studied by 
 instructed minds ; they have been accepted. And the con- 
 sequence has been great industrial production, the fruit of which 
 all the rest of the world has received. But in England, " Well, 
 ah ! yes. It has not been tried. It is difficult/' It is given to 
 somebody who has not disciplined himself like the Germans do, 
 and he finds difficulties, and then gradually the thing is dropped. 
 For you must remember that because the masters, the heads, the 
 capitalists, have not got sympathy with this self-preparation for 
 the difficult tasks, there is no career for the young men who are 
 willing to study. What can they do ? They are paid salaries 
 quite insufficient for the training they have to go through, and 
 for the learning they have acquired. The consequence is, that 
 when I am asked how it is that we are so poorly represented in 
 the industrial ranks by chemists, I say, " Make a career for your 
 young chemists, and then you will see." We have not done so. 
 
 Now that is the cause, and, so far as is material, the sole 
 cause, of the German supremacy. Remember that there is not 
 one single thing in which we are at a disadvantage by natural 
 position. It is perfectly true that in the Creation, by some 
 blunder, the most valuable deposit of potash was put in the 
 centre of Germany, but we can get potash from elsewhere if we 
 want it. As to coal, and the sources of the coal-tar industry, we 
 have them in richer quantity than even Germany itself. The 
 one thing is the difference in the human element, and this 
 is not a difference in intellectual capacity, but in the industry and 
 in the willingness to study to the bottom the subject with which 
 you have to deal. 
 
 Gentlemen, that is my opinion of the cause of England's 
 inferiority, and I ask myself at once, " Is that a cause which must 
 permanently operate ? " The answer is, of course, * c No." But 
 it is for us to reform ourselves. Otherwise no relief can come. 
 
MANUFACTURE OF DYES IN ENGLAND 357 
 
 It is impossible that we can get a chemical industry like the 
 German's unless we are willing to train ourselves for it, to have 
 faith in it, to embark our capital in it, and in this way take the 
 steps which lead to it. Consequences follow causes in this 
 world ; and to hear people grumble at this difficulty about the 
 dyes when one thinks they have neglected all the necessary 
 causes to produce the industry, would make me feel almost 
 impatient if it did not make me sorrowful. 
 
 The question is, then, has the condition of things become so 
 permanent that it is too late to do anything ? Here I confess 
 that I feel cheerful. Let me deal for a moment with the 
 difficulties that appear to one. The first is that there is a lack of 
 the necessary technical skill. I have a great difficulty in returning 
 a polite answer to that. To my mind it is nonsensical. We 
 have the command, and we shall in peace still more have the 
 command, of abundant technical skill to create the industry. You 
 must remember this, that in the long catalogue of dyes (over 
 which I have been poring all these weeks) the vast number are 
 dyes the processes for the manufacture of which are well known. 
 I do not say that the man who is practised in it will not get a 
 better yield, or that his handiwork will not be more certain. Of 
 course it will. But there are no people better qualified to learn 
 by experience than the English people themselves, and the whole 
 of these dyes can be manufactured with as great certainty in 
 England if we put up the proper plant and choose the proper 
 men to guide it. 
 
 Now let me go to the more recent dyes, those that have 
 hardly made their way into commerce, but the qualities of 
 which show that they will be very desirable. It is perfectly 
 true that if you want to manufacture these on an industrial 
 scale you will previously have to study in the laboratory, by 
 observation of the reactions, how to get the best results. But 
 you will be astonished how few the processes are in this great 
 industry, and the extent to which they are simply the repetition 
 of the same processes with different substances and under 
 different conditions. The sole difficulty which separates brilliant 
 success from comparative failure is that study has shown how 
 to regulate the conditions so as to make the results most 
 favourable. 
 
 There is no mystery to the chemist. There is that which 
 requires study before he can arrive at it ; but if you are going 
 
358 THE BRITISH COAL-TAR INDUSTRY 
 
 to be daunted by that, then the rest of my speech will not 
 interest you. So that the objection of not having abundant 
 technical skill to carry out any industry that we form is in my 
 opinion absolutely baseless. 
 
 Well, then I am told, " It is impossible to compete. 
 There are works with a capital of a hundred millions in Germany. 
 Your foes are willing to crush you by every means they know, 
 and those means, I can assure you, are various and effective." 
 
 Well, that is a very great fact, but if you tell me that it is 
 impossible for manufacture to go on in spite of this competition 
 1 will ask you to turn your eyes not only to this country, but 
 even to Germany, where you find firms outside these great 
 combinations, who in their own particular line have a successful 
 business, and even an export business, in which they contrive to 
 flourish not to make the gigantic profits of the rings, but still 
 to make fair industrial profits. In your own country you have 
 them. You have firms that in spite of the pressure of the 
 Germans manufacture at a profit. And side by side if you 
 look back with these firms there were many other firms whom 
 the Germans feared sufficiently either to buy out or to crush 
 out. When they realised that they were capable of producing 
 in competition with them they felt that at great cost they must 
 get rid of them. That, surely, is proof that competition in pro- 
 duction is not impossible. 
 
 Remember this, that success in production depends no 
 doubt on cheapness, but if you produce on what I may call an 
 economical unit, that is on a scale which is adequately great, 
 the advantages from doing it on an enormous scale are very 
 small in comparison. And certainly England, with its rich 
 market, its demand for dyes and many of these demands 
 capable of being satisfied with comparatively few dyes, England 
 can certainly start an industry in which the manufacture is on 
 such a large scale that it can challenge if not equal the economies 
 of the biggest works. 
 
 Let me now go to the third objection which is raised to the 
 possibility of our competing, and it is raised in connection with 
 the suggestion that I am defending here the consequence of 
 my conclusion that a great national effort should be made, and 
 a large company formed capable of producing dyes on a scale 
 sufficient to satisfy the English demand. It is a very curious 
 one, and yet you have all heard it. I remember saying to one 
 
MANUFACTURE OF DYES IN ENGLAND 359 
 
 with whom I was discussing the matter, and who knew well 
 the trades of Lancashire and Yorkshire "Don't you think 
 it would be of infinite value to England to have a company 
 which would for ever secure its dyeing and textile .industries, 
 aye, and the great pigment industries, which must not be for- 
 gotten, from being overcharged for their dyes ? " The man 
 said, " But that is not what I am thinking about. I am not 
 thinking about being overcharged. My fear is we shall be 
 undercharged ! " 
 
 Here I was trying to protect an English industry. I was 
 talking to a man vitally interested in it, and what was his fear ? 
 His fear was that the consequence of our doing it would be that 
 you would get dyes cheaper than they could be made, and that 
 was what was frightening him. I will tell you what it reminded 
 me of. Supposing there was a question of building a defensive 
 fort to protect the vital part of a country, to protect, we will 
 say, London, and the objection was raised, " Oh, but if you 
 build it as strong as that nobody will attack it, and then how 
 will you defend the spending of your money ? " 
 
 I ask you to think of this objection seriously, and in the 
 light in which I am putting it to you. To my mind it is the 
 most universal and the meanest of all the things which influence 
 men's minds on this subject. They are afraid it will be too 
 successful. They know that if they do not make such a 
 company they will be ruthlessly overcharged by the Germans. 
 Of that there is not a fraction of doubt. They know that if 
 they do form this company that cannot be so, and the probability, 
 they think, is that your great industries will have their dyes 
 cheaper even than they can be made. They must realise that 
 that, to a nation which has a world-wide commerce, is a boon 
 beyond estimation, and yet they are afraid, if they put their 
 money in, that they will win this boon for their fellow- 
 countrymen. 
 
 What does it mean ? It is that ineradicable defect of the 
 English mind, if it has not by travel or study or reading got 
 rid of its insularity. I used to sit for a constituency, an 
 agricultural one in the South, and I never could get out of the 
 head of any one farmer that his real competitor was the man 
 living next door to him. He did not realise that this insular 
 idea of being afraid that the man next door will get the better 
 of you for a penny, or that his goods, which are not quite as 
 
360 THE BRITISH COAL-TAR INDUSTRY 
 
 good as yours, will still be treated alike with yours, is the thing 
 which has prevented all co-operation among them in the south. 
 While Denmark, a poor country, has been rolling up its wealth 
 by combined action, our English people stand apart, and are still 
 as unfitted for helping the wholesale trade of the world as if it 
 were almost fifty years ago. 
 
 What this objection means is, you are afraid that Mr So- 
 and-So, who has not subscribed, will get all the benefit you have 
 won by your subscription. You do not doubt that you will win 
 it for your country. You do not doubt that you will win it 
 for yourselves. You do not doubt that in this way, so far from 
 industries being harried, they will be put in an undeservedly 
 fortunate position. And yet you do not want to do it because 
 the gain will come to your trousers pocket instead of to your 
 waistcoat pocket. Instead of coming in dividend it will come 
 in the lower price of dyes. 
 
 So, if I could believe that the formation of this company 
 would force the Germans for one year or two years or twenty 
 years to sell their dyes at less than cost price, I should come to 
 you and say, " You have got a chance now to save yourselves 
 and England, and to put yourselves and England in a position 
 of vantage in competition in foreign lands that you have not 
 deserved but that you are going to get." 
 
 But, gentlemen, I frankly tell you that I do not think you 
 are going to have such a good time as that. 1 will tell you why. 
 If a great company is formed that is efficient and that produces, 
 as an efficient English company will produce, at fair prices, it 
 will cost the Germans too much to sell below cost price here. 
 For this reason : once satisfy the English market with these low- 
 priced dyes, and you free the output of this company to go to 
 those Eastern markets, out of which the Germans derive the 
 profits which enable them to fight you, and you can sell there 
 at fair prices, and the Germans will either lose the market or 
 there, too, they must drop their prices. 
 
 I think you will find that dropping prices all round is not a 
 good way of increasing your profits. You are business men. I 
 am not a business man, but my opinion is that they will find 
 that it is better to leave you alone, better to leave you to supply 
 yourselves than to set free such a formidable output as a great 
 company would make to compete with them in the other markets 
 of the world. 
 
MANUFACTURE OF DYES IN ENGLAND 361 
 
 What does all this lead to ? It leads to this. In my opinion 
 there must be, in order to give England industrial freedom in 
 this group, which is almost, I should think, or quite, the 
 greatest group of its industries there must be a great national 
 effort to create a company, a company working under the con- 
 ditions of other companies, suffering from its blunders and 
 profiting by its wisdom. 
 
 But there are three conditions, and unless those three con- 
 ditions are all satisfied it will be a failure. 
 
 The first condition I lay down is that it must be large. 
 Politically, the Germans are frankly the foes of small nations. 
 They consider that small nations are to be eaten up. Industrially, 
 this great embodiment of the German idea, the combination of 
 the dye manufacturers, behaves to small manufacturers exactly 
 as Germany seeks to behave to small nations. It is hopeless to 
 suppose that if there are sporadic attempts, all small, they will 
 not be either dragged into a combine, or crushed by a combine, 
 or in one of the many other ways, which you all know, put out 
 of existence. It must be large, and therefore independent, and 
 therefore beyond attack. 
 
 There is another thing. It must be national in this sense : 
 it must be removed for ever from the temptation of listening 
 itself to the voice of the charmer and entering into a combine. 
 
 We must have a company that is not only powerful, but one 
 the loyalty of which is necessarily beyond all doubt, and that we 
 can only get if it is assisted by the Government, on the terms 
 that the Government can stop it from ever entering into the 
 backward path which would ruin its national utility. Most of 
 you like the idea, I can see, of its being large, and of its being 
 kept always true and faithful to its national aim. 
 
 Now I am going to tell you the third condition, which 
 concerns you. It must be co-operative. The producer must 
 be the consumer. You will never link up all these industries 
 unless those who use the dyes are included, the textile people 
 as well as the dyeing people, and those who are in the great 
 pigment trade. Unless all those who are about to consume 
 have an interest in the production, and therefore supply a pre- 
 ferential market, you will never succeed in making the com- 
 pany relieve the national need. If 1 had had the millions I 
 wanted offered me on the Stock Exchange for a company which 
 would be free from all trammels, which would have no connection 
 
362 THE BRITISH COAL-TAR INDUSTRY 
 
 with the trade, the shares of which would be bought as the others 
 that are called industrials on the Stock Exchange, where every 
 penny of profit it made would be squeezed out of it for the 
 benefit of the then holders of the shares, who would care nothing 
 for the holders of the next year or for the future of the company, 
 I would have said at once, " It is doomed to failure," and its 
 failure would be only the more marked because it was gigantic. 
 
 You must realise that you, the consumers, should loyally all 
 combine with the producing company, and then I will defy the 
 German or any other competition to break down that bond of 
 union. Remember this. The only thing which will ensure a 
 combine or a ring against failure is co-operation between the 
 producer and the consumer. I remember one of the earliest 
 cases that came before me. It was a case of a very great in- 
 dustry, and we were told that it was entirely in the hands of 
 such a ring formed in such a city in Germany. Well, what 
 happened ? We got the producers and the consumers together 
 and said, " If you will produce the article yourselves you can 
 defy rings. How can they touch you ? (It happened to be a 
 question of a metal.) You can buy in the markets of the world. 
 It is produced everywhere. No one can run up the price against 
 you, and therefore the worst that can happen is that you are on 
 equal terms with them." 
 
 Now some of you will say, " Oh, yes, but is not this a viola- 
 tion of the chief commandment, c You shall buy in the cheapest 
 market * ? " Is it ? Remember this, that in considering what 
 is cheap you must not look at the money that passes, but at the 
 consequences of the purchase too. The man who says, " I will 
 buy for five years at a discount of five per cent., with the certainty 
 that I shall have to pay fifteen per cent, more for the next ten 
 years," and thinks he is buying in the cheapest market, is, I 
 suggest, a bad student of economics. It is not buying in the 
 cheapest market if you buy something which destroys your real 
 security for cheapness, which prevents you from being over- 
 charged. And I am perfectly certain that when the idea of loyal 
 co-operation gets hold of Lancashire and Yorkshire the foes of 
 England in the industrial world will begin to tremble. We 
 have had a time of peace in England, and we have never thought 
 of dangers industrial or national. But there are these dangers, 
 and even though there may not be another war, as we trust there 
 will not be, there is perpetual war going on industrially, and it 
 
MANUFACTURE OF DYES IN ENGLAND 363 
 
 is not based on the ideas of each man doing his best and of fair 
 sale and fair purchase. It is based on what in the industrial 
 world corresponds to war in the political world, and if you do 
 not realise that, if you will not stand by one another as producer 
 and consumer, and you let the producer go down under his 
 enemies, so that in turn they have the mastery of you, then all 
 I can say is that as consumers you have been buying in the 
 dearest market, and you will deserve the consequences that 
 you get. 
 
 Now, gentlemen, I have come to the conclusion of which 
 I told the Government. I have nothing to do with the particular 
 form in which the Government have followed out that for 
 which I am responsible as an adviser. You must have a large 
 company a company with national control so far as to keep 
 it in the right path ; and you must have a company which is 
 co-operative between the producer and the consumer. If you 
 do that, I can warrant it a long and successful life ; but if you 
 attempt to leave out any one of these three essentials, it is pre- 
 doomed to failure. 
 
 Just let me say one or two words in conclusion. Supposing 
 our War Minister had been in the last few years buying in the 
 cheapest market for the sake of cheapness, and that he had 
 had the munitions of war manufactured by Krupps, of Essen. 
 Gentlemen, I think he would have been lynched about three 
 months ago. You would have realised when the moment of 
 need came that your sources of supply were cut off. Now, 
 gentlemen, there are munitions of peace which are essential for 
 the defence of the great industries of the country, which are 
 vital. There are munitions of peace as to which you have to 
 take the same precautions as in regard to munitions of war. 
 
 You have to realise that, so far as it is possible, a country 
 should be in such a position that if its supplies are cut off, for 
 any reason whatever, from outside, it should be able to supply 
 itself. Of course, we realise that in raw materials and in many 
 other things we must depend on supplies from outside, and that 
 is the reason why we are a nation that spends so unstintingly 
 on its fleet. But this is no question of getting raw materials 
 from a foreign country. It is a question of being at the mercy 
 of a country, not friendly disposed, in a matter where we could 
 make ourselves independent ; and it is a case in which we know 
 perfectly well what are the morals of that country in regard to 
 
364 THE BRITISH COAL-TAR INDUSTRY 
 
 its behaviour to other nations. Therefore I say you must look 
 upon it as if it were one of those necessary munitions of peace 
 which you must see adequately manufactured among yourselves. 
 
 Some will say there is none here, I trust what I heard 
 of a great dealer saying, " Oh, but I am a business man. I only 
 look at things as business propositions, and a tenth of a penny 
 would make me buy everything from Germany rather than from 
 England." At that very moment tens of thousands of men 
 were exposing their lives in the trenches to protect that man 
 and his money. I wonder how many would have been there if 
 it was always thought a brilliant thing for a man to look on every- 
 thing from the point of view of a business proposition ? 
 
 If that is being done by the recruits, what are you and I going 
 to do for our country ? You cannot go to the trenches, and yet 
 I believe you are all willing and burning to do what you can 
 for your country. Well, this is your part. You can protect 
 your country by taking care that when peace comes it shall be 
 under no subordination. That is what I ask you to do. A 
 great writer has said, " There is nothing more desirable in life 
 than to be wise at a great moment." This is a great moment. 
 Be wise. 
 
XXVII.: 1915 
 
 GERMAN CHEMICAL INDUSTRY THIRTY 
 YEARS AGO 
 
 BY THE RIGHT HON. SIR HENRY ROSCOE, F.R.S. 
 
 (Journal of the Society of Chemical Industry^ 3Oth January 1915, p. 65) 
 
 THE following short report, written by myself for the Royal 
 Commission on Technical Instruction, of which I was a member, 
 was printed in 1882. This shows that even in those early years 
 the Germans had seized upon the methods which have made 
 their chemical industries so successful, and that money cannot 
 secure success unless it is accompanied by perfect scientific 
 method, and above all by the recognition of the importance of 
 original investigation : 
 
 ON THE INFLUENCE OF TECHNICAL EDUCATION ON CERTAIN 
 BRANCHES OF CHEMICAL INDUSTRY 
 
 We have here collected our notes on certain special industries, 
 viz. (i) chemical colours, (2) beet-sugar, and (3) the alkali trade, 
 upon which the influence of technical education is plainly 
 observable. 
 
 Influence of Technical Training on the Chemical Colour Industry 
 of Germany and Switzerland 
 
 Among the coal-tar colour works visited by the Commissioners 
 were those erected on the banks of the Rhine at Basle by Messrs 
 Bindschedler & Busch. These works, though far less extensive 
 than those of Messrs Meister, Lucius & Brttning, at Hdchst, 
 or of the Baden Aniline and Soda Works at Ludwigshafen, are 
 
 365 
 
366 THE BRITISH COAL-TAR INDUSTRY 
 
 carried on in a no less scientific spirit, and the general method of 
 working adopted in all these establishments is identical. 
 
 The first principle which guides the commercial heads of all 
 the Continental colour works is the absolute necessity of 
 having highly trained scientific chemists not only at the head of 
 the works, but at the head of every department of the works 
 where a special manufacture is being carried on. In this respect 
 this method of working stands in absolute contrast to that too 
 often adopted in chemical works in this country, where the con- 
 trol of the processes is left in the hands of men whose only rule 
 is that of the thumb, and whose only knowledge is that bequeathed 
 to them by their fathers. 
 
 On entering the works of Messrs Bindschedler & Busch one 
 is struck, in the first place, with the adaptation of means to ends, 
 with the substantially built, well-lighted, well-ventilated work- 
 shops, and, above all, with the all-pervading cleanliness and 
 neatness. But it is not of these things that we now desire to 
 speak, but rather of the method by which their business is 
 conducted. In the first place, then, the scientific director 
 (Dr Bindschedler) is a thoroughly educated chemist, cognisant 
 of and able to make use of the discoveries emanating from the 
 various scientific laboratories of the world. Under him are 
 three scientific chemists, to each of whom is entrusted one of the 
 three main departments, into which the works are divided. Each 
 of these head chemists, who have in this instance enjoyed a 
 thorough training in the Zurich Polytechnic, has several assistant 
 chemists placed under him, and all these are gentlemen who 
 have had a theoretical education in either a German university 
 or in a Polytechnic school. An important part of the system 
 has now to be noticed, viz., that directly under these scientific 
 assistants come the common workmen, who have, of course, no 
 knowledge whatever of scientific principles, and who are, in fact, 
 simple machines, acting under the will of a superior intelligence. 
 The many and great advantages of this arrangement are patent 
 to all ; and the fact of having men of education and refinement 
 in positions of this kind renders the foreign manufacturer who 
 adopts this system less liable to annoyance and loss (from 
 sources which we need not more nearly specify) than his English 
 competitor, who works on a different plan. 
 
 So much for the personnel of the works. Now for the mode 
 in which they carry on their work. To begin at the beginning, 
 
GERMAN CHEMICAL INDUSTRY 30 YEARS AGO 367 
 
 we find no less than ten well-equipped, airy, experimental 
 laboratories in these works, perfectly distinct from the workshops 
 where the manufacturing processes are carried on. In these ten 
 laboratories, the chief departmental chemists and their assistants 
 work out their investigations respecting the production of new 
 colouring matters, or the more economic manufacture of old 
 ones. To assist them in their work, a complete scientific library 
 is at hand containing all the newest researches, for these, as we 
 have said, form the material out of which the colour-chemist 
 builds up his manufacture, and no sooner do the results appear 
 of a perhaps purely scientific research which may possibly yield 
 practical issues, than the works-chemist seizes on them and 
 repeats these experiments, modifying and altering them so as at 
 last to bring them within the charmed circle of financial success. 
 
 Thanks to Dr Bindschedler, we are able to quote a specially 
 representative case, and a clear description of one such case is 
 worth a host of generalities. Through the original investigations 
 of Messrs Emil and Otto Fischer, the attention of the manufacturer 
 was drawn to the leuco or colourless base obtained by the action 
 of benzaldehyde on dimethylaniline, inasmuch as they stated 
 that the salts of these colourless bases become green on exposure 
 to air. Founded on these observations, an endeavour was made 
 to effect the practical manufacture of a green colouring matter 
 by oxidation of these colourless bodies. In order to attain the 
 desired end, the following investigations had to be made by the 
 chemist and his assistants who were to conduct the operations : 
 
 (1) A cheap method had to be found for manufacturing 
 benzaldehyde. 
 
 (2) A profitable mode of making the leuco base had to be 
 worked out. 
 
 (3) The proper oxidising agents and their best method of 
 application had to be determined. 
 
 (4) The best method of purifying and of crystallising the 
 green colouring matter had to be discovered. 
 
 The laboratory experiments on the above points having 
 proved so far successful as to give prospects of good results, 
 operations on a somewhat larger scale were started, and these 
 yielding a satisfactory issue, the manufacture proper of the 
 colouring matter, now well known as malachite green, on the 
 technical scale was commenced, all the operations being watched 
 by and constantly being under the control of the chemists. But 
 
368 THE BRITISH COAL-TAR INDUSTRY 
 
 even now their scientific work is by no means ended. Continuous 
 laboratory experiments go on for the purpose of rinding improve- 
 ments in the mode of manufacture. Thus, for example, the 
 improved yield, both as to quality and quantity, of the benzal- 
 dehyde is a matter of investigation. Again, the synthetic pro- 
 duction of the pure leuco base by a more direct process is sought 
 for, so as to get rid of loss in working, and to obtain a yield as 
 close as possible to that pointed out by theory. In the same 
 way improvements in the materials used for oxidation, and in 
 their application, are made, so as to effect the oxidation quanti- 
 tatively, without the formation of by-products. Lastly, the 
 action of various solvents is examined, so as to obtain the best 
 form of the crystallised colouring matter. As indicating the 
 value of these improvements made after the colour became a 
 marketable article, it is only necessary to state that the price 
 of the crystallised oxalate has been reduced from 2 to 1, 43. 
 per kilo. 
 
 The foregoing may serve to give a picture of a really 
 scientifically conducted works, where each step in advance is 
 made systematically, as the result of a well-devised plan of 
 operations. This is, indeed, the only means of progress, and 
 this fact is so well recognised in Germany that each of the much 
 larger colour works at Hochst and Ludwigshafen possesses a 
 staff of from thirty to forty well-paid and thoroughly trained 
 chemists to conduct their operations. 
 
 But we are, of course, far from believing that because the 
 methods adopted in these foreign colour works are scientific and 
 productive of good, those made use of in all English works must 
 therefore be unscientific and bad. Taking the whole applications 
 of chemical science we may, no doubt, with truth say that the 
 English industrial chemists have been at least as successful 
 commercially and certainly as productive in new and important 
 discoveries as their Continental rivals. The Germans and 
 Swiss, however, have been and still are distinctly before us, not 
 only in the facilities which they possess of obtaining the highest 
 technical training in their numerous universities and polytechnic 
 schools, but what is even more to the point before us, is the 
 general recognition of the value and importance of such training 
 for the successful prosecution of any branch of applied science. 
 
 The following statistics give some idea of the magnitude 
 of the colour works of Messrs Meister, Lucius & Brtlning, 
 
GERMAN CHEMICAL INDUSTRY 30 YEARS AGO 369 
 
 at Hflchst, near Frankfort, referred to above, and founded 
 in 1862. 
 
 The establishments occupy an area of 1 50 acres, of which 20 
 are covered with buildings. The staff includes 51 scientific 
 chemists, 50 foremen, 15 managers and engineers, and 77 clerks 
 and commercial men, with 1400 workpeople. The works possesses 
 its own railways, 41 boilers, with a heating surface of 4000 square 
 yards, and 71 motors, either steam, water, or gas engines. The 
 workmen and officials are domiciled in houses belonging to the 
 company, and restaurants, baths, sick clubs and pension funds 
 have been established for the good of the employes. There is 
 also a fire-brigade with 5 hand engines and i steam fire-engine. 
 The total supply of water, from 145 fire-cocks, amounts to 30,000 
 cubic feet per hour. 
 
 In 1882 the products of these works amounted to : 
 
 (1) 6,600,000 Ib. weight of alizarin. 
 
 (2) 2,200,000 Ib. weight of aniline oil. 
 
 (3) 1,540,000 Ib. weight of aniline, resorcin, and naphthol. 
 
 Colours 
 
 The following are the separate products classed together 
 under the last head : 
 
 Aniline and aniline salts. 
 
 Fuchsine (no arsenic used in its preparation). 
 
 Methyl violet. 
 
 Green and blue colours. 
 
 Eosin colours. 
 
 Naphthol colours. 
 
 Alizarin and artificial indigo. 
 
 Quinolin derivative (kairin, a new substitute for quinine). 
 
 Acids. 
 
 The most important raw materials employed in manufacturing 
 the foregoing products are as follows : 
 
 40,000 tons coal. 
 3,000 tar products. 
 2,400 caustic soda. 
 400 potash salts. 
 2,900 carbonate of soda. 
 17,400 sulphuric acid. 
 
 24 
 
370 THE BRITISH COAL-TAR INDUSTRY 
 
 10,100 tons various other acids. 
 1,500 iron borings and filings. 
 
 250 wood spirit and spirits of wine. 
 1,000 various chemicals. 
 6,800 common salt. 
 2,050 carbonate of lime. 
 
 The whole of the sulphuric, hydrochloric, and nitric acids 
 used is made on the works. 
 
 From about 70 to 80 per cent, of all the aniline colours manu- 
 factured are exported, the remainder being used in Germany. 
 
 About 90 per cent, of the total make of alizarin is exported 
 chiefly to England, but considerable quantities find their way to 
 America, Russia, France, Holland, Spain, and Italy. 
 
 One of the most recent and most interesting additions to the 
 above list of products is a derivative of quinolin, termed kairin, 
 lately discovered by Emil Fischer. This substance, which is 
 now being made at Hochst at the rate of about 22 Ib. daily, has 
 been shown to possess important febrifuge properties, even 
 exceeding quinine in activity, and it is not impossible that this 
 artificial product obtained from coal tar may be the means of 
 supplanting altogether the natural alkaloid. The importance of 
 this discovery, should it serve the above purpose, can of course 
 hardly be overrated, and it will then add another and most 
 striking example to the numerous ones which already exist of the 
 immense importance to the human race of researches in purely 
 scientific organic chemistry, which at one time appeared to have 
 no practical value or possible application. It may, therefore, 
 serve again to point the moral, which cannot be too strongly 
 insisted upon, that it is only by the highest and most elaborate 
 achievements of pure scientific investigation that the greatest 
 practical advantages to mankind can be secured. 
 
XXVIII. : 1915 
 
 THE MANUFACTURE OF DYESTUFFS 
 IN BRITAIN 
 
 BY PROFESSOR W. M. GARDNER, M.Sc., F.I.C. 
 
 I 
 
 A SUMMARY AND AN APPEAL 
 (Nature^ 2ist January 1915, p. 555) 
 
 THE speech of Lord Moulton in Manchester on 8th December 
 1914 was a notable event, even in these days of strenuousness 
 and surprise. For although he was careful to disclaim any official 
 sanction of the views he expressed, it was common knowledge 
 that the Government had requisitioned his services in investigat- 
 ing the question of the shortage of dyestuffs, and had based its 
 policy largely on the advice he gave as the outcome of his 
 investigation. 
 
 The general outline of the crucial position in which the 
 British textile trades are placed at the present time is well 
 known. At least 1,500,000 operatives are engaged in the 
 various branches of the trade, which has an annual value of 
 200,000,000. Nearly the whole of this vast industry depends 
 for its commercial success upon the use of dyestuffs, which cost 
 about 2,000,000 per annum, and only about 10 per cent, of the 
 necessary quantity of dyestuff is made in this country. Before 
 the war, between 80 to 90 per cent, of our dyewares was 
 imported from Germany, and this supply is now entirely cut off. 
 Unless, therefore, immediate steps are taken greatly to increase 
 our national output and the supply from neutral countries (chiefly 
 Switzerland), a catastrophe will very quickly overtake the great 
 textile and associated industries. 
 
372 THE BRITISH COAL-TAR INDUSTRY 
 
 The magnitude, gravity, and imminence of the crisis clearly 
 pointed to the necessity for Government action, and a " Chemical 
 Supplies Committee " was appointed to confer with the Board of 
 Trade on the position. This committee included a number of 
 well-known chemists, and manufacturers and users of chemicals 
 and dyestuffs. The investigations of Lord Moulton and of this 
 committee are understood to have formed the basis from which 
 the offer of the Government was developed, but the committee 
 was apparently not responsible for the details of the scheme for 
 the establishment of a large Joint-stock Dye-manufacturing 
 Company, which was made public on 22nd December 1914. 
 
 Prior to this, on roth December 1914, a meeting of large 
 users of dyes was held at the Board of Trade, at which a resolu- 
 tion was unanimously passed welcoming the assistance of the 
 Government in a national effort to increase the British supply of 
 dyes. A small committee, representative only of the users of 
 dyes, was appointed, and elaborated the scheme to which reference 
 has already been made for the formation of a manufacturing 
 company. 
 
 An influential committee, appointed by the Society of Dyers 
 and Colourists, has also made exhaustive inquiries on the tech- 
 nical side and has accumulated much valuable information. 
 
 It is well known that there are enormous difficulties involved 
 in establishing on a permanent basis the manufacture of dyes on a 
 scale adequate to supply our needs, and that without Government 
 or legislative assistance they might well prove insurmountable ; 
 and the action of the Government in proffering such broad- 
 minded and generous support has received, as it deserved, the 
 recognition of all parties. 
 
 The German colour industry is probably the most compli- 
 cated, most highly developed, and most profitable of all her great 
 industries. The capital invested in it is about .12,000,000, and 
 the German exports of dyes and associated products in 1912 
 were valued at 10,600,000. The organisation, both for pro- 
 duction and for marketing and distribution, is wonderfully 
 efficient, and above all the Germans have long realised that in 
 this branch of industry the scientific mind and scientific method 
 must be predominant, not only in the laboratory and in the 
 works, but in the management. The boards of directors of their 
 large works are virtually committees of technical and commercial 
 experts who are in intimate touch with the respective branches of 
 
MANUFACTURE OF DYESTUFFS IN BRITAIN 373 
 
 the works of which they have special knowledge. In a word, 
 the trained man of science has in these works come to his own, 
 and a proper recognition of the necessity of this is vital to the 
 development of the British colour industry. 
 
 The reasons for the predominance of Germany in this 
 particular industry have been frequently and variously stated, 
 but it is now generally conceded that there is no lack of highly 
 trained chemists in this country competent to build up a com- 
 mercially successful enterprise. With regard to other factors, 
 we have, of course, a superabundance of the coal-tar products 
 which form the basis of the manufacture, but the manufacture 
 of certain essential reagents, e.g. fuming sulphuric acid, though 
 already existing, will have to be greatly increased. 
 
 Government assistance will be required in regard to the 
 provision of cheap alcohol, and the resources and skill of the 
 chemical engineer will be heavily drawn upon to provide the 
 essential apparatus. A great number of chemists will be needed 
 to work out the details of known processes, first on the laboratory 
 scale, and later on a bulk basis, and the well-equipped laboratories 
 and staffs of the universities and larger technical institutions 
 might well be pressed into service for much of the preliminary 
 work. Many chemists will also be required for developing new 
 processes and for other research work, because of no other in- 
 dustry can it be so truly said that stagnation spells failure. 
 
 The great complexity of the manufacture of dyestuffs is not 
 due to the use of a large number of raw materials, the direct 
 products from coal tar being only nine or ten. By chemical 
 treatment these are, however, transformed into 250 to 300 
 different intermediate products which, in their turn, yield some 
 1 200 chemically distinct dyestuffs. In some processes of manu- 
 facture high temperatures and pressures are required ; in others 
 the temperature must be reduced, and a large refrigerating plant 
 is an essential feature of a colour works. 
 
 Surely, then, it is abundantly evident that the technical expert 
 must be the preponderating element in the dye factory, and that 
 he must have a large share in the management and control. 
 The British custom of entrusting the management of large 
 concerns to financiers, commercial magnates, and "men of affairs" 
 has done much to retard the scientific development of our 
 industries, and the adequate representation of the technical expert 
 on the directorate is vital to the success of the new scheme. 
 
374 THE BRITISH COAL-TAR INDUSTRY 
 
 Lord Moulton laid down three propositions with regard to 
 the proposed new British dye-manufacturing company. It must 
 be large enough to be able to face severe competition at the end 
 of the war. It must be, and must remain, entirely British, and 
 it must be co-operative ; and all these conditions are fulfilled by 
 the scheme put forward. It is proposed that the share capital 
 shall be 3,000,000, and the Government offers to supplement 
 this by a loan of 1,500,000 at 4 per cent, and repayable in 
 twenty-five years. The four and a half millions of capital thus 
 proposed is probably ample to establish and develop an industry 
 which would make us independent of imported products. 
 
 The proposals with regard to co-operation are that dyers and 
 others associated with the consumption of the products, e.g. 
 spinners, manufacturers, merchants, textile machinists, etc., 
 should take shares in the new company and thus become 
 interested in its success. This is quite sound and receives 
 general acceptance, but certain suggestions in the prospectus with 
 regard to a pro rata subscription appear to be unworkable. 
 
 The Government reserves the right of appointing two 
 directors of the company, and it is much to be regretted that the 
 opportunity has not been taken of giving a wise lead in regard 
 to the character of the directorate, by stipulating that the scientific 
 technologist should be adequately represented. 
 
 Another feature of the scheme propounded by the committee 
 is that certain existing colour works are to be taken over by the 
 new company to form the nucleus of development. The 
 resources of these works are to be extended as rapidly as possible 
 in order to cope with immediate necessities and prevent an actual 
 famine in dyewares in fact, large extensions are at the present 
 moment being made. 
 
 A point which presents some difficulty in adjustment is the 
 relationship of the new company to existing British dye-produc- 
 ing firms, or such as may be established in the future. It is 
 obviously not desirable to stifle private enterprise by anything in 
 the nature of a monopoly supported by the Government, but the 
 existence of successful German firms which are outside the two 
 great " Interessengemeinschafte," or rings, indicates that the 
 difficulty is more apparent than real. A somewhat cognate 
 matter is the future relationship of the new company to the 
 Swiss firms which are importing to us during the present crisis. 
 
 The various criticisms of the Government schemes which 
 
MANUFACTURE OF DYESTUFFS IN BRITAIN 375 
 
 have been offered refer, not to general principles, but in almost 
 all cases to more or less important details. The general outline 
 of the scheme the establishment, by co-operation of those 
 specially concerned, of a new company with great resources and 
 financially aided by the Government has received general 
 approval, and the unprecedented step taken by the Government 
 has been applauded by men of all parties, as meeting an industrial 
 crisis in a bold and statesmanlike manner. In response to this, 
 and in recognition of a national emergency, it is the obvious duty 
 of all who are commercially interested to deal with the question 
 from the national rather than from the individual point of view. 
 Support of a scheme for the manufacture in Britain of British- 
 used dyes is, at its lowest estimate, an essential business insurance, 
 and on a higher plane it is helping forward a movement to free 
 our great textile industry from the danger of German domination. 
 Apart altogether from the commercial aspect, there is, therefore, 
 a great obligation of patriotism involved. The scheme put 
 forward possibly as a ballon d'essai as regards details certainly 
 requires modification, but from it can be elaborated a national 
 and co-operative effort which is bound to succeed. Let us all 
 take as a starting-point of our deliberations that the thing must 
 be done, and then the details of how to do it will fall into proper 
 perspective. 
 
 Finally, it may be pointed out that incidental advantages of 
 enormous national value will accrue as the result of the successful 
 fruition of this dyeware manufacture scheme. The necessity 
 for dealing with our industries from a national, rather than an 
 individualistic, point of view will be more fully recognised by the 
 Government and by the public. The necessity for the use of 
 scientific method and control of our industries will be strongly 
 emphasised. The claims of patriotism and the value of co- 
 operation in commercial matters will receive fuller consideration. 
 And lastly, the establishment of a powerful company for the 
 manufacture of organic dyestuffs will afford protection to our 
 great industries concerned in the manufacture of inorganic 
 chemicals, an attack on which was beginning to be organised. 
 
 Now is our opportunity, and everything is propitious. 
 Patriotism and self-interest are alike clamouring for the establish- 
 ment of a large dye-manufacturing concern, and the Government 
 offers its support. One essential thing may, however, be over- 
 looked the new company is foredoomed to failure unless a 
 
376 THE BRITISH COAL-TAR INDUSTRY 
 
 scientific rather than a purely commercial spirit permeates the 
 management, and an appeal is made to the Government and to 
 the eminent business men forming the committee who have 
 issued the scheme that in its final form it may include a full 
 recognition of this fundamental point. 
 
 II 
 
 THE GOVERNMENT'S MODIFIED SCHEME 
 (Nature^ 25th February 1915, p. 700) 
 
 The discussion on the various aspects of the problem of pro- 
 ducing in this country an adequate supply of dyestuffs proceeds 
 without intermission. The question has for some time assumed 
 a national aspect and has been the subject of Parliamentary debate 
 or question on at least three occasions. It has also been debated 
 at meetings of the Chambers of Commerce in the chief industrial 
 centres, and people most directly interested have had many 
 opportunities of expressing their opinions at meetings of their 
 various organisations, or at gatherings specially convened for 
 the purpose. 
 
 To a great extent the discussions have centred round the 
 adequacy and equity of the commercial proposals involved in 
 the official scheme now before the public. These have received 
 much more general acceptance than those put forward in the 
 first scheme, and it appears probable that the committee has now 
 received promises of support to an amount representing a 
 substantial proportion of the initial capital proposed for the 
 new company. 
 
 The members of the committee themselves admit that it is 
 an easy matter to criticise the scheme adversely, and it is 
 obviously impossible to devise a solution of the problem 
 satisfactory to all minds. 
 
 If the matter is to be viewed as an ordinary commercial 
 proposition, if questions of free trade or protection are to be 
 taken into account, or if early dividends are to be assured, then 
 any scheme which might be put forward could be shown to be 
 unworthy of support. But whilst criticism on these lines has 
 been plentiful, there has latterly been a rally of support by those 
 taking broader views a support which has probably been largely 
 induced by a sense of national need, and has certainly been 
 
MANUFACTURE OF DYESTUFFS IN BRITAIN 377 
 
 greatly developed by the action of the Government in offering 
 to endow the research work which is essential to the extent of 
 ; 1 00,000. This action has engendered a feeling of confidence 
 that the Government will take any further steps which the future 
 may show to be vital to the success of the British dye- 
 manufacturing industry. 
 
 It is to be hoped that the committee in charge of the scheme 
 will shortly be able to announce the results of its inquiries, and 
 that these will show that the great textile trade of the country 
 has responded adequately. In the meantime, the arrangements 
 for carrying out the necessary preliminary chemical work should 
 be proceeded with. 
 
 A Mobilisation of Chemists 
 
 Speaking in Bradford on 8th February, the present writer 
 advocated immediate action by the Government or the Board 
 of Trade Advisory Committee in the direction of utilising the 
 services of British chemists. There is on one hand a large 
 amount of chemical work to be done before the industry can 
 be greatly developed, and on the other there are a great number 
 of well-staffed and well-equipped laboratories in our universities 
 and technical colleges which might render great service to the 
 industry. To avoid wasteful duplication of work and to co- 
 ordinate the results, it is essential that some organised scheme 
 and allotment of work should be arranged, and it is suggested 
 that a conference of those concerned should be held at an early 
 date to formulate such a scheme. Even if to-morrow the whole 
 of the available chemical force set to work on some organised 
 plan, it would not be any too soon to get the necessary informa- 
 tion together for the use of the existing works and the new 
 works when they are started. 
 
 The urgency of this action is further shown by a resolution 
 passed by an important meeting held in Manchester on i6th 
 February, which was presided over by Sir Charles Macara. 
 The resolution, which was carried unanimously, stated : "That 
 in the opinion of this meeting the Government would do well 
 to organise immediately the present chemical talent in the 
 country with a view to chemical research being undertaken 
 for, and on behalf of, all manufacturers interested, and that 
 the services of these experts should be available for all desirous 
 of availing themselves thereof.'* 
 
378 THE BRITISH COAL-TAR INDUSTRY 
 
 The adoption of such a plan for bringing the educational 
 institutions more closely into touch with the industries would 
 in all probability mark the beginning of a new era in which both 
 would benefit. The more intimate association of professors of 
 chemistry with chemical industry would introduce into the works 
 that higher ideal and broader scientific spirit upon which successful 
 research and development depend, whilst the schools would 
 benefit by the great incentive of practical reality. 
 
XXIX.: 1915 
 THE CHEMICAL INDUSTRIES OF GERMANY 
 
 BY PROFESSOR P. FRANKLAND, F.R.S. 
 [Abstract] 
 
 (Nature, nth March 1915, p. 47; Journal of the Society of Chemical 
 Industry^ April 1915, p. 307) 
 
 THE interest and importance of the subject at the present time 
 are sufficiently obvious. In outlining some of the origins of 
 chemical industry in Germany, the lecturer pointed out how the 
 royal house of Prussia had been frequently associated with 
 chemical enterprise. The Markgrave John was actually sur- 
 named " the Alchemist " ; the Great Elector was a patron of 
 chemistry and provided a laboratory at Potsdam for the celebrated 
 Kunkel, one of the first to discover phosphorus, and who also 
 effected great advances in the manufacture of glass. Frederick 
 the Great established the Royal Berlin porcelain factory, which 
 still occupies some of the original premises. In the same reign 
 also the chemist Marggraf made those classical investigations on 
 the occurrence of sugar in the vegetable kingdom which later led 
 to the foundation of the beet-sugar industry, which was initially 
 subsidised by Frederick William III., the founder of the Uni- 
 versity of Berlin in 1809. (^ n I 9 I 4> tne Berlin University had 
 12,585 students, and received an annual grant from the State of 
 more than 200,000.) 
 
 Great industries have developed out of these early steps. 
 From the discovery of phosphorus came the match industry. 
 The German annual production of matches is 4,600,000 ; the 
 British production in 1907 amounted to 775,000, whilst the 
 British consumption in 1910 was estimated at 1,300,000. 
 Again, the porcelain and pottery manufacture had attained great 
 dimensions in Germany, the exports in 1912 amounting to 
 
 379 
 
380 THE BRITISH COAL-TAR INDUSTRY 
 
 3,556,000, whilst the glass industry was even on a larger scale, 
 the recent annual exports being more than 7,000,000. Great 
 inconvenience in connection with all scientific work is at present 
 being experienced through the absence of German glass. The 
 important cyanide industry may be said to have taken its origin 
 from the accidental discovery by Diesbach, of Berlin, of Prussian 
 blue in the first decade of the eighteenth century. Germany's 
 annual production of cyanides is now estimated at 10,000 tons 
 (650,000), or about one-half of the world's production. 
 
 The beet-sugar industry exemplifies how agricultural pro- 
 duction can be improved by systematic research such as has been 
 bestowed on it by Germany ; thus : 
 
 In 1840 100 Ib. of beet yielded 5*9 Ib. sugar. 
 
 1850 7-3 
 
 1870 8-4 
 
 1890 12-5 
 
 1910 15-8 
 
 Again, in 
 
 1871 mean yield of beet per hectare of land was 246 quintals. 
 19! >i 3 
 
 And again, in the economy of manufacture 
 
 In 1867 coal used on 100 Ib. beet . . . . 35 Ib. 
 
 1877 ... 24 
 
 1890 . 10 
 
 19 -7 
 
 The former supremacy of Great Britain in the manufacture 
 of the common chemicals sulphuric acid and soda was referred 
 to and compared with the production of these materials in 1910. 
 
 PRODUCTION IN TONS, 1910 
 
 Germany. England. France. United States. World. 
 
 Sulphuric acid . 1,250,000 1,000,000 500,000 1,200,000 5,000,000 
 Soda . . . 400,000 700,000 200,000 250,000 2,000,000 
 
 The substitution of the ammonia-soda for the earlier Le Blanc 
 soda process, and of the contact for the time-honoured leaden 
 chamber process of sulphuric acid manufacture, had no doubt 
 greatly assisted both Germany and America in becoming inde- 
 pendent of the British manufacture of these chemicals. 
 
 During the past twenty-five years the manufacture of chlo- 
 rine and caustic soda by the electrolysis of common salt (sodium 
 chloride) has been realised and rapidly extended. This process 
 
THE CHEMICAL INDUSTRIES OF GERMANY 381 
 
 is carried out on a very large scale in Germany, where extensive 
 use is made of liquefied chlorine. The production of electrolytic 
 chlorine is attended with the simultaneous evolution of large 
 quantities of hydrogen gas for which uses have been found; 
 thus, for filling the dirigible balloons upon which such hopes of 
 conquest have been based by Germany, whilst in the oxyhydrogen 
 flame it has been employed for welding, for the cutting even of 
 thick iron structures, and for the manufacture of artificial gems. 
 The artificial production of gems corundum, ruby, sapphire, 
 etc. was discovered in France by Michaud, Verneuil, and 
 Paquier, and has been greatly taken up by the Elektrochemische 
 Werke at Bitterfeld, in Germany. More than a ton of these 
 gems, which are identical in chemical composition with the natural 
 gems, are said to be annually produced. Other more important 
 uses for hydrogen have been found for the hardening of fats, and 
 still more recently for the synthetic production of ammonia to be 
 presently referred to, and which is an industrial achievement of 
 the first magnitude. Cheaper sources of hydrogen than the 
 electrolytic method have been introduced, and notably that de- 
 pending on the production of water-gas (consisting of equal 
 volumes of hydrogen and carbon monoxide) from steam and 
 coke at a red heat, the carbon monoxide being subsequently 
 separated from the hydrogen by liquefying it by means of the 
 low-temperature apparatus of Carl von Linde, of Munich. 
 
 AMMONIA, NITRATES, AND FIXATION OF FREE NITROGEN 
 
 As is well known, one of the most important problems at 
 the present time is to provide the world with nitrate when the 
 deposits in Chile shall have been exhausted. The problem is 
 bound up with the still wider one of the fixation of atmospheric 
 nitrogen. This again, as is well known, is now accomplished on 
 a large scale by the production of nitric acid from atmospheric 
 nitrogen and oxygen by means of the electric furnace of Birkeland 
 and Eyde, or by the production of calcium cyanamide by passing 
 atmospheric nitrogen over heated calcium carbide. Both these 
 processes involve the use of the electric furnace, in the former 
 for effecting the union of the nitrogen and oxygen, and in the 
 latter for the preliminary production of the calcium carbide. 
 Abundant water-power being necessary for the economic opera- 
 tion of the above processes, Norway has become their chief centre, 
 
382 THE BRITISH COAL-TAR INDUSTRY 
 
 whilst Germany has sought other means of nitrogen-fixation which 
 could be carried on within her own territories. The synthesis of 
 ammonia from hydrogen and atmospheric nitrogen under a pressure 
 of 200 atmospheres and at 500 C. in the presence of a catalyst, 
 has been successfully worked out by Haber in conjunction with 
 the Badische Anil in- und Soda-Fabrik, and a plant capable of 
 yielding 130,000 tons of sulphate of ammonia per annum was to 
 have been ready in 1915. The second step in the German pro- 
 gramme was to convert the ammonia into nitric acid by burning 
 it in air in the presence of a catalyst. In this way it is hoped to 
 make Germany independent of foreign countries for the nitrate 
 required in the manufacture of explosives. It is asserted that 
 this independence Germany has actually secured at the present 
 moment. 
 
 EXPLOSIVES 
 
 Of the modern high explosives, gun-cotton was discovered 
 by Schoenbein and by Boettger in 1846. The manufacture of 
 nitroglycerine (discovered by Sobrero in Paris in 1847) was 
 first realised by the Swede, Alfred Nobel, in 1862, and it was 
 Nobel who first adapted these powerful explosives for ballistic 
 purposes. Trinitrotoluene, of which so much has been heard 
 recently, was first proposed for filling shells by Haessermann in 
 1891. It is said to be surpassed, both as regards safety and 
 disruptive effect, by tetranitro-aniline discovered in England by 
 Dr Fluerscheim. The great magnitude of the German explosives 
 industry is seen from the following figures : 
 
 Tons. 
 
 Total German production of explosives . . . . 40,000 
 or about one-tenth of the estimated world production. 
 
 Germany exported in 1908 to the value of . . 1, 000,000 
 1912 3,000,000 
 
 ARTIFICIAL SILK 
 
 This remarkable industry, originated by Count Chardonnet 
 in France in 1891, has also been largely developed on German 
 soil. The German production amounts to about 2000 tons 
 annually (1,200,000) out of a total world production of about 
 7000 tons. French, German, and British patents have largely 
 contributed to the success of this industry. 
 
THE CHEMICAL INDUSTRIES OF GERMANY 383 
 
 INDUSTRIES DEPENDENT ON SYNTHETIC ORGANIC CHEMISTRY 
 
 It is in respect of these industries that the world is learning 
 that Germany holds the undisputed supremacy. It is in Germany 
 alone that manufacturers have been found prepared to embark 
 their capital and undertake industrial enterprises of the first 
 magnitude on the advice of the organic chemist. The success 
 which has been achieved by the German manufacturers of artificial 
 dyestuffs, drugs, and perfumes, and the hegemony which they 
 have secured in this branch of industry, has been the frequent 
 subject of warning by professors of chemistry in this country for 
 upwards of a generation. The seriousness of the situation which 
 has arisen through the neglect of those warnings is seen from the 
 following figures : 
 
 Annual value of dyestuffs used in Britain .... ^2, 000,000 
 
 trade in which these dyes are employed . 200,000,000 
 
 Workmen dependent on this trade, 1,500,000 
 
 Total value of dyestuffs imported (1913) into Britain . 1,892,055 
 
 ,, from Germany . . 1,730,821 
 
 Less than one-tenth of the annual value of the dyestuffs 
 consumed in England is produced in this country. Thus, by 
 controlling the dyestuff industry, Germany indirectly holds in 
 her grip the whole of the textile industry. 
 
 Much inconvenience has been experienced also in the shortage 
 of artificial drugs and consequent high prices, more especially at 
 the beginning of the war, as even the simplest of these products 
 were almost exclusively made in Germany. The manufacture of 
 some of these is, however, now being successfully carried on in 
 England. 
 
 Again, the shortage of organic chemicals required for research 
 purposes, which practically all come from Germany, is occasioning 
 most serious difficulties in our university laboratories. 
 
 For the manufacture of dyestuffs and similar synthetic pro- 
 ducts Germany was formerly largely dependent on England 
 for the raw material coal-tar. But in this case, again, the 
 ambition of Germany to become in all respects independent and 
 self-contained has led her in recent years to make the most 
 strenuous efforts to recover the maximum amount of coal-tar 
 both from the manufacture of gas and from coke-ovens, which 
 endeavour has been assisted by the enormous growth in her iron 
 and steel industries. Thus in 1897 Germany obtained only 
 
384 THE BRITISH COAL-TAR INDUSTRY 
 
 52,000 tons of coal-tar from coke-ovens, whilst in 1908 she 
 obtained no fewer than 632,400 tons from that source, besides 
 300,000 tons from the manufacture of gas. Thus at the present 
 time the German output of coal-tar about equals, if it does not 
 exceed, that of England. 
 
 The German production of artificial perfumes is said to 
 amount to a value of about 2,500,000 annually. In this 
 department of applied chemistry, again, one of the first steps 
 was made by the late Sir William Perkin, by the synthesis in 
 1868 of coumarin, the much-valued odoriferous principle of 
 woodruff {Asperula odorata]. 
 
 The effect of artificial synthesis on the price of natural 
 perfumes may be gathered from the following examples : 
 
 
 Price of I kilo. 
 
 Natural. 
 
 Synthetic. 
 
 Coumarin .... 
 Vanillin .... 
 Heliotropin .... 
 
 
 
 25 
 5 
 
 s. d. 
 i 5 o 
 
 I IO O 
 IO 
 
 The proposal of the Government to assist the British coal-tar 
 colour industry is being watched with the greatest interest both 
 by manufacturers and chemists. The problem of relieving the 
 immediate shortage during the war must be carefully distin- 
 guished from the later problem of securing the independence 
 of the home industry after the war by greatly increasing the 
 British output. The realisation of the latter object will be 
 attended with the greatest possible difficulty. The industry will 
 require " nursing " for a great many years. The undertaking 
 must be possessed of such elasticity that it can ramify into other 
 branches of chemical or other industry whenever advantageous 
 opportunities arise for such departures. 
 
 The great magnitude of the German coal-tar colour industry 
 may be gathered from the fact that the two groups into which 
 the principal firms are associated have at the present time a total 
 share capital of about 12,000,000, on which a dividend of about 
 28 per cent, is paid. In 1912 Germany produced dyestuffs to 
 the value of 12,500,000, of which to the value of 10,000,000 
 were exported. 
 
THE CHEMICAL INDUSTRIES OF GERMANY 385 
 
 The above facts speak for themselves and proclaim in the 
 most convincing manner the stupendous progress which has been 
 made by Germany in the chemical industries during the past 
 forty years. It is equally certain that England, once pre-eminent 
 for chemical manufactures, has not progressed at the same rate and 
 is at the present moment suffering much inconvenience through 
 being so largely dependent on German chemical products of one 
 kind and another. The country is now reaping the harvest of 
 humiliation which it has sown for itself in spite of the warnings 
 repeated ad nauseam during a whole generation. The systematic 
 neglect of chemical science and the failure by manufacturers to 
 utilise the services of highly qualified chemists, could only lead to 
 the result that all the industries which are dependent on a pro- 
 found knowledge of chemistry should tend to disappear from our 
 midst and pass into the hands of those who are prepared, not only 
 to apply new chemical discoveries to industry, but even to prose- 
 cute the most varied chemical investigations in the hope of sooner 
 or later making discoveries which shall be of advantage to their 
 commercial undertakings. The mischief caused through the neg- 
 lect of chemistry by practical men in this country has been so subtle 
 that to a large extent it has remained concealed from the average 
 man of intelligence and from the governmental classes. During 
 the past forty years our country has been accumulating wealth 
 in an altogether unprecedented fashion, so that the loss or 
 restriction of some industries appeared a matter of no importance 
 to political observers taking only a broad and superficial survey 
 of the national resources. The whole of our arrangements have 
 evolved during the past half-century on the assumption that this 
 country would never again be engaged in a European war, whilst 
 still more recently the new democracy has vainly boasted that 
 it could prevent such a war by means of a general strike. The 
 year 1914 has seen the dissolution of many fools' paradises 
 and has given the coup de grace to all these vain imaginings, with 
 the result that we find our vast textile industry in serious peril 
 because the much smaller dyestuff industry has been complacently 
 allowed to slide into the hands of our sagacious and more pains- 
 taking enemies. The same carelessness and want of foresight 
 had even allowed us to become dependent on Germany for some 
 of the most important materials used as explosives, e.g. trinitro- 
 toluene, and for many of the most valued drugs required alike 
 by our Army, Navy, and civil population. 
 
 25 
 
386 THE BRITISH COAL-TAR INDUSTRY 
 
 The complete breakdown in our supply of fine chemicals, 
 which is the direct outcome of the disregard of the constant 
 warnings emitted by scores of British chemists, has led the 
 Government of the day to intervene and attempt to remedy 
 the intolerable state of affairs which has arisen in connection with 
 the supply of coal-tar colours. 
 
 We devoutly hope that success will attend the endeavour 
 to establish the coal-tar colour industry in these Islands on the 
 largest possible scale. Whatever the ultimate scheme adopted 
 may be, I would venture to point out that it must be based on 
 a clear understanding of the following considerations : (i) That 
 the provision of the required chemicals during the continuance of 
 the war is one thing, and that their production on a commercial 
 basis after the cessation of hostilities is quite another matter. 
 (2) It appears to me that in order to provide the needful supply 
 during the war, the only reasonable course is to assist in every 
 possible way those firms which are already making similar or 
 closely allied products so as to enable them to produce their 
 present goods on a larger scale, and as far as practicable to 
 undertake the manufacture of others which are urgently re- 
 quired. The immediate problem will be also greatly facilitated 
 by utilising supplies obtainable from neutral powers, and more 
 especially from Switzerland, which is the only country, other 
 than Germany, in which the manufacture of dyestuffs and similar 
 chemical products has been vigorously prosecuted. (3) As regards 
 the prospects of the home industry after the war, it will require 
 " nursing." I use the term advisedly in order to obviate the 
 employment of another and much more familiar one which is so 
 dear to some politicians and so hated by others ; it will require 
 nursing for a much longer period of time than has hitherto been 
 mentioned. In this connection I would point out that the sum 
 of 1 0,000 a year for ten years, which it has been proposed to 
 guarantee for research purposes, is absurdly inadequate. (4) If 
 the industry is to prosper it will not only have to manufacture 
 materials already known, but also continually to be introduing 
 new products of its own discovery, as well as constantly to be 
 seeking to produce more economically a great number of auxiliary 
 chemicals required in the manufacturing processes. It is also 
 essential that the undertaking should branch out into the 
 manufacture of other materials as occasion may arise for 
 advantageously utilising by-products. (5) The competition 
 
THE CHEMICAL INDUSTRIES OF GERMANY 387 
 
 which the industry will have to suffer from Germany is likely 
 to be much more serious than is generally supposed, because it 
 must be remembered that England only takes, as we have seen, 
 about one-fifth of the total German exports of dyestuffs, so that 
 it would be comparatively easy for German firms specially to 
 reduce the price of the goods sent to England. They have 
 already done this in America when attempts have been made to 
 start a dyestuff industry there. It is particularly significant, and 
 augurs ill for the prospects of this scheme to rehabilitate the 
 coal-tar colour industry, that the latter has failed to flourish 
 anywhere excepting on German soil, and that countries with 
 fiscal systems entirely different from our own have been no more 
 successful in this respect than have we ourselves. (6) It will 
 certainly be necessary that expert chemical knowledge should 
 in the future be much more highly remunerated than it has been 
 in the past, otherwise the supply of able and properly qualified 
 men will not be forthcoming. The flow of men of high-grade 
 intelligence into a profession is determined by the prizes which 
 the profession has to offer, in the form of money and social 
 position. Consider the great stream of able men who are attracted 
 to the English Bar, in which profession the prizes, although 
 limited in number, are of the most substantial kind, with the 
 result that the successful leaders are selected by the fiercest 
 competition in a very wide field. If there is to be a large influx 
 of high intelligence into the chemical profession, it will be 
 necessary that there should be some very different prizes from 
 the paltry bait which is offered at the present time, for the study 
 of chemistry in this country now only draws those men who 
 either have or think they have an overpowering zeal and passion 
 for the science, to which they devote themselves against the 
 advice of their friends. Notwithstanding the absence of material 
 inducements, I venture to say without fear of contradiction that 
 there is more original investigation being prosecuted in this 
 country by chemists than by any other body of British men of 
 science, and this I attribute to the fact that such a large proportion 
 of our number have either been at German Universities or are 
 the pupils of those who have been at these centres of research. 
 Nor are any of us, I am sure, even during this unfortunate crisis, 
 unmindful of the hospitality and the inspiration which we have 
 received in the schools of the enemy. (7) If the proposed under- 
 taking is to succeed, real chemists must be on the directorate, 
 
388 THE BRITISH COAL-TAR INDUSTRY 
 
 and in a sufficient proportion to give effect to their views. Many 
 men of science are excellent business men. What does experience 
 teach in the case of flourishing chemical industries which we for- 
 tunately still have amongst us ? What does not the firm of 
 Messrs Brunner, Mond & Co., for example, owe to the late Dr 
 Ludwig Mond, F.R.S. ? (8) In attempting to establish a com- 
 mercially successful coal-tar colour company on a large scale in this 
 country, I venture to think that the Government have undertaken 
 a task which they will find to be surrounded with difficulties of 
 quite a different order from those which they have had to 
 encounter in some of their most striking previous legislative acts, 
 such as the provision of salaries for members of Parliament, the 
 granting of old-age pensions, and the establishment of a compul- 
 sory system of insurance. These are matters in which if the 
 Government dictate we are obliged to obey ; but the commercial 
 success of an industry which is based upon progressive scientific 
 investigation depends upon factors so subtle and elusive that 
 they cannot be coerced even by a majority of the House of 
 Commons. (9) If the chemical industries are to be rehabilitated 
 in this country, there must be a complete change in the attitude 
 of mind towards science in general, and towards chemical science 
 in particular, amongst the influential classes of the population, 
 and it will certainly not be effected by following the precept 
 " Business as usual," but by pursuing a policy which is the 
 exact opposite of what is implied by that phrase. 
 
XXX.: 1915 
 
 PATENT LAW REFORM 
 BY J. W. GORDON, K.C. 
 
 (Journal of the Royal Society of Arts, I2th March 1915, p. 356) 
 
 (THE first portion of the paper gives a very interesting summary of the 
 development of technical education in England and in Germany?) 
 
 In the year 1867 all the world was looking admiringly upon 
 the high development and great prosperity of British industry. 
 Just as we to-day speak with respect of the technical educational 
 institutions of America, France, Switzerland, and Germany, so in 
 1867 those other countries were speaking with the like respect of 
 our widely diffused mechanics' institutes and art schools. Sir 
 Bernhard Samuelson, who was in personal contact with our 
 industrial neighbours while at the same time he was an enterprising 
 industrial captain himself in this country, was by no means 
 satisfied that these developments, which attracted the favourable 
 notice of our neighbours, were sufficient to do justice to our- 
 selves. At great personal trouble and expense he produced a 
 report of which Mr Mundella, the Minister for Education, in 
 1 88 1 spoke in high praise, as a State document. In 1882 Sir 
 B. Samuelson became the Chairman of the Royal Commission 
 known as the Duke of Devonshire's Commission. In 1897 the 
 same Commission produced a second report, in which the further 
 development of the technical education and institutions of 
 Germany was made the subject of comparison with the past and 
 with our then existing system. The appearance of the second 
 report of the Commission gave rise to an important newspaper 
 discussion which furnished the occasion for a very remarkable 
 utterance by Sir Bernhard Samuelson, in a short letter which 
 appeared in the Times of 25th January 1897, and runs as 
 follows : 
 
 389 
 
390 THE BRITISH COAL-TAR INDUSTRY 
 
 "In your leader on the report of my late colleagues on 
 technical progress in Germany, you refer to the fact that the 
 production of dyes from coal tar, in which we have been so 
 completely distanced by the Germans, was originated by Dr 
 Perkin, and, it might be added, by Dr Hofmann, in this country. 
 
 " It is not generally known that we lost this manufacture 
 because the trade in England was shut up for fourteen years by 
 a master patent whilst no controlling patent had been sanctioned 
 in Germany, so that anyone could take up the manufacture there ; 
 the result being, of course, development abroad in place of 
 stagnation at home. 
 
 " At the present time we in this country are handicapped as 
 much as before, but from an opposition (sic) of things. The 
 Germans, having taken the lead with their acquired experience 
 and large capital, keep it by patenting their new processes in this 
 country, but carry out their manufacture abroad. So long as 
 they keep our market supplied, which they take care to do, 
 nobody is at liberty to make the patented articles here." 
 
 The case to which allusion was made in the last paragraph 
 was an action tried in our own courts in 1883, anc ^ brought 
 by the Badische Chemical Factory against Levinstein & Co., 
 a firm of dye manufacturers in Manchester. Seldom has an 
 action of greater practical importance been the subject of pro- 
 ceedings in a court of law. 
 
 The German patentees in that case were the inventors of a 
 dyestuff, a chemical body having a definite chemical composition 
 and a specific name. It may be sufficiently identified by speaking 
 of it as a sulpho acid of a coal-tar product yielding red and brown 
 dyes. In respect of the dyestuffs which they were the first to 
 produce, the German patentees obtained a British patent which 
 was unquestionably good. Those dyestuffs, however, were of 
 no appreciable commercial value. 
 
 The patent was taken out in 1878, and it was five years later 
 that the action against Levinstein came to trial. The patentees 
 then complained that a very successful red dye which Levinstein 
 manufactured was an infringement of their patent. In the view 
 which the court took of the nature of the patent this claim was 
 upheld, and judgment accordingly was given in their favour. But 
 the circumstances were very singular, and such as to place the 
 court in a difficult position when deciding upon the issue of fact. 
 It was proved that the dye which Levinstein manufactured could 
 
PATENT LAW REFORM 391 
 
 not be produced by the processes which the inventors had 
 described, indeed could not be produced by any process which 
 was known to the inventors. The successful dye, which was 
 taken to answer to the chemical composition of the patented 
 invention, was produced by a secret process, and special arrange- 
 ments were made for taking the evidence in such a manner that 
 the Levinstein secret was not disclosed except confidentially to 
 the court and its officers. The patentee, therefore, although he 
 was allowed to restrain the second inventor from working his 
 own invention in this country, did not acquire a knowledge of 
 the nature of that invention. Thus the action resulted in a 
 deadlock, and the operation of the patent law in this case was 
 to banish the manufacture of the patented dye from this country 
 altogether. The patentee could not make it because he did not 
 know how, the real inventor could not make it because he was 
 restrained by an injunction of the court. So it happened that 
 by this perverse operation of the patent law a patent, which had 
 been granted with the avowed object of introducing into this 
 country the manufacture of the sulpho-acid dyestuffs, operated 
 to prevent their introduction. In the end the manufacture was 
 carried on in Holland, where the German patentees had been 
 unable to obtain a patent. No statistics have been published 
 from which the value of the dye industry which was thus trans- 
 ferred to Holland can be ascertained, but credible information 
 goes to show that the cloth sent from Manchester to Holland to 
 be dyed with Blackley red represented an industry which, in the 
 aggregate, was worth many millions of pounds, and Sir Bernhard 
 Samuelson's warning is of special importance at a moment when 
 the investment of a large sum of money is in contemplation with 
 the object of establishing an industry similar to that which was 
 so ruthlessly destroyed by legal process in 1883. 
 
 Now, in a case like this it is quite impossible to attribute the 
 loss of the industry to any defect in our system of technical 
 education. In 1883 a Patent Act had been passed by which 
 provision was made, among other things, for the remedying of 
 the mischief which this case illustrates. It is not, however, to be 
 supposed that the draftsman of that statute had the facts of the 
 Levinstein case in mind. That, indeed, was impossible. The 
 Act was passed in 1883, and the action was only tried in that 
 year. The consequences of the decision in that action could not 
 possibly have been known until a later date. But although it 
 
392 THE BRITISH COAL-TAR INDUSTRY 
 
 had not been illustrated on so large a scale, the mischief was 
 perfectly well known to students of our industrial development 
 in 1883. It is not surprising, therefore, to find that an attempt 
 was made to remedy the mischief. 
 
 It has been shown that the operation of the patent law in 
 the Levinstein case was to render the use in this country of a 
 valuable invention impossible, and to banish the resulting industry 
 to Holland. It needs no argument to show that that is a 
 complete miscarriage. The object of the patent law is to 
 facilitate the introduction of new manufactures within the realm. 
 Whether we look upon the patent as an instrument of public 
 policy, or as a reward granted to a meritorious inventor, the 
 result from this point of view is the same. The merit of the 
 inventor or the object of the policy, as the case may be, is to 
 secure the advantage of an improvement in manufacture for the 
 benefit of the people of this realm. In law, no less than in 
 policy, the outcome of the Levinstein case was absurd and 
 lamentable. How, then, could such a result come about ? The 
 answer to that question is that it came about by the operation of 
 the rule which makes an injunction by the court the remedy for 
 an infringement of patent right. 
 
 In spite of the stringent provisions of the Statute of Mono- 
 polies (1624) the injunction is to-day what it was in the days of 
 Elizabeth and James I., the main support of patent right, and, as 
 the case quoted shows, it has been used in modern times with 
 effects even more disastrous for the industry of this country than 
 in those ancient days, when it aroused the hostility of Lord Coke 
 and the antagonism of a reforming Parliament. 
 
 Enough has been already said about the mischievous effect 
 of this particular injunction upon the dyeing trade of Lancashire. 
 But the facts cover a very much larger field than this particular 
 sulpho-acid dye, a field in fact much larger than the field of 
 dyestuffs, a field which is larger even than the whole chemical 
 industry. But we are more immediately concerned with its 
 bearing upon the proposal to establish dye manufacture upon a 
 very extensive scale within this country. 
 
 From that point of view the important fact in the Levinstein 
 case is, not that the manufacture of a particular dye was pro- 
 hibited within the realm, but that the way of improvement was 
 closed. The peculiar mischief of this decision was that it made 
 it more advantageous for an inventor who improved upon the 
 
PATENT LAW REFORM 393 
 
 original patent to go to Holland and practise his improved 
 invention as a secret process than to practise it in this country 
 under the provisions of our patent law. To establish such 
 a state of things was obviously cutting at the root of 
 development. A few carefully disposed patents can, under such 
 a system, block the whole development of an industry against all 
 the world except only those privileged people who chance to be 
 the holders of the pioneer patents. It is a matter of no con- 
 sideration that these pioneer patents themselves may be perfectly 
 worthless for all practical purposes. It is their existence, not 
 their merit, which constitutes the strength of the patentee's 
 position. 
 
 This situation was clearly apprehended at a very early date in 
 the history of the chemical industry by our German competitors. 
 A system of blocking patents has been an organised industry 
 with the great German manufacturing chemists at least since the 
 year 1883 ; and when we hear of the large staffs which they keep 
 employed upon research work in their factories, it is well to 
 remember that, over and above those results of this laboratory 
 industry which take effect in improved processes and products, 
 there is a large output of novelties which are improvements only 
 in a legal sense ; the real value of which is that they eventuate 
 in patents of this blocking type which close the avenues of 
 improvement to other inventors. 
 
 It is impossible from any available data to ascertain to what 
 extent the British chemical industry has been sapped by means 
 of such mischievous patents, but this system of sapping has 
 been systematically and extensively developed, and it has had an 
 immense success. 
 
 In all these cases the cause of our weakness is the injunction. 
 It is to be understood that, according to the practice which 
 prevails to-day, a perpetual injunction is granted as a matter of 
 course to protect a patentee who has successfully established his 
 patent rights against an infringer. 
 
 Such being the mischief, we may now turn to consider what 
 are the remedies which Parliament has provided. The earliest 
 attempt Was embodied in a section (22) of the Patent Act of 
 1883, which provided a remedy which has come in recent years 
 to be well known under the style of a compulsory licence. 
 
 If this contrivance of a compulsory licence had been effective, 
 it would have met the whole difficulty. It would have prevented 
 
394 THE BRITISH COAL-TAR INDUSTRY 
 
 the mischiefs which have arisen, and would probably have placed 
 the patent law of this realm in an entirely sound position. But 
 a very hard fate has pursued the reformers of our patent law. 
 This provision was still-born and never produced its intended 
 effect, a result which was due to faults of draftsmanship. 
 (A detailed discussion of the Patent Act 0/1883 follows here?) 
 The provisions of the Act of 1883 concerning compulsory 
 licences were never tested experimentally, for, although several 
 petitions were lodged and carried through to a conclusion, they 
 were all carried through under such unfavourable conditions that 
 anything more than an unsatisfactory success was rendered im- 
 possible. It is not surprising, therefore, that the agitation 
 already referred to for a reform of the Act of 1883 should have 
 gathered head and eventually should have prevailed in Parlia- 
 ment. In 1900 a Departmental Committee was appointed to 
 consider further remedial legislation, and in particular to advise 
 Parliament as to the adoption of the Continental provision of 
 the compulsory working within the realm of patented inventions. 
 The Committee reported against the compulsory working pro- 
 vision, and in favour of a reference of petitions for compulsory 
 licences to the High Court. The report contained also some 
 other suggestions, and in the ensuing year Parliament proceeded 
 to legislate on lines generally indicated by the Committee. In- 
 stead, however, of adopting the suggestion that petitions for 
 compulsory licences should go to the High Court, Parliament 
 took the extraordinary course of sending them for consideration 
 to the Privy Council. This expedient did not help matters at all. 
 The division of authority was still as marked and as mischievous 
 as when the petition was sent to a referee, and the practice of 
 the Privy Council tended rather to aggravate than to reduce the 
 costs incidental to the carrying of the petition through. So far 
 the last case was distinctly worse than the first, and in 1907 
 Parliament proceeded to deal with the matter for a third time. 
 
 The Act of 1907 was closely modelled upon the German 
 patent law. Accordingly a new remedy was introduced in the 
 shape of a condition making the working of a patented invention 
 within the realm compulsory, but the nature and measure of the 
 working to be required and the conditions which furnished an 
 excuse or imposed liability upon a patentee were left to be settled 
 by the judges in the administration of the law. It was probably 
 a wise expedient on the part of Parliament to leave these matters 
 
PATENT LAW REFORM 395 
 
 thus in a plastic condition to be moulded and fixed by the action 
 of the judicature. The idea no doubt was that the obligation of 
 compulsory working would, on the one hand, discourage the 
 practice of taking patents for the purpose of blocking an industry, 
 and, on the other hand, would secure the development within the 
 realm of industries which are protected by patent right. The 
 Act has only been in operation for a period of about seven years, 
 and it is too soon perhaps to attempt anything like an estimate 
 upon historical foundations of its possible outcome. It may be 
 pointed out, however, that it has not had very much effect so far 
 upon the chemical industry. To those who have a practical 
 acquaintance with the conditions of the problem this will not be 
 surprising. The complications which it presents in its judicial 
 aspects are enormous. In part they may be illustrated by the 
 facts of the Levinstein case which have been described. In such 
 a case as that, for instance, where there was no market for the 
 goods which the patentee could manufacture and a large market 
 for the infringing goods which he did not know how to make, 
 what is the patentee's obligation under the law of compulsory 
 working ? Must he manufacture, to satisfy the law, a certain 
 quantity of unmerchantable goods, or is he to be held liable 
 to manufacture the improved goods whose production is the 
 infringer's secret ? The inherent difficulties are such that nothing 
 would be less surprising than that it should be found in the end 
 to be what it appears to have been in the beginning, an expedient 
 wholly ineffective for any useful purpose. 
 
 Such being the situation which has actually arisen, it will be 
 useful to consider the bearing of this situation upon the proposal 
 now made to establish, in competition with the German industry, 
 a self-sufficient industry in this country in the manufacture of 
 dyestuffs. We may take it for granted on this occasion that 
 no insuperable difficulty will arise. So far as research and 
 technical education are concerned there is not likely to be the 
 smallest difficulty about securing, and at once securing, the 
 necessary trained skill. 
 
 Let us assume that the works are started and in successful 
 operation. That fact will not make any difference to the subsist- 
 ing patent rights in this country of which, as is well known, 
 a very large proportion are held by foreigners and others whose 
 interest it is to favour the foreign competition with this domestic 
 industry. Now it is clear, therefore, that there will be a strong 
 
396 THE BRITISH COAL-TAR INDUSTRY 
 
 disposition to repeat the Badische coup of 1883, and then, adopt- 
 ing the language of the judgment in that case, we may say that 
 notwithstanding " the great knowledge, great skill, and great 
 perseverance " which will be brought to bear in building up 
 these industries, the law will be invoked to say that the processes 
 so developed cannot be used in the production of the colouring 
 matters manufactured because the production of those colouring 
 matters is protected by patent rights. It may at once be admitted 
 that the new institution will be placed in a very different position 
 from that which was occupied by the defendant in the Badische 
 and Levinstein action. In the present case there is a possibility 
 of applying to the Board of Trade for a compulsory licence, and 
 if it were certain that such a proceeding would succeed it would 
 in substance remove the difficulty. There would still be an 
 important question of procedure to be considered, but that is 
 probably not of great importance. It cannot, however, be taken 
 for granted that an application for a compulsory licence would 
 succeed. The grounds on which such an application can be made 
 are strictly limited and, in fact, very narrow. If the patentee 
 himself takes adequate steps to supply the British market with 
 his patented goods, then, according to the interpretation adopted 
 by the courts of this provision of the statute, no order for a 
 compulsory licence can be made. Now, in the case at least of 
 important goods for which a large and profitable market exists, 
 there seems to be no conceivable reason why the foreign patentee 
 himself should not supply the demand. It is quite true that 
 he may be called upon to conduct his manufacture within the 
 realm, but he cannot be called upon, as matters stand, to grant 
 a licence to the new institution. He may prefer to remain an 
 active and privileged competitor with the new institution, and 
 so, although with diminished power of mischief, may still succeed 
 in casting his blight upon the undertaking. The carrying on of 
 the new industry under these conditions would seem likely to be 
 extremely fruitful of litigation, but by no means equally assured 
 of success ; for if it were possible to close any particular 
 manufacture down as the result of a successful patent action, 
 then it cannot be denied that nobody at the present moment 
 is in a position to say what precise field of industry will in the 
 end remain open to the proposed institution. This is the 
 difficulty with which the promoters are faced. The research 
 work of the laboratories of which we have lately heard so much 
 
PATENT LAW REFORM 397 
 
 has resulted in an immense and extremely intricate network of 
 patents designed to protect, by their entanglement, the whole 
 field of chemical industry, which the Germans have made their 
 own. Hitherto these entrenched patents have afforded very 
 efficient protection partly, no doubt, because the defence of the 
 British industry has been left to the uncoordinated efforts of 
 British manufacturers, who have been attacked one at a time and 
 beaten in detail. It does not, of course, follow that it would be 
 equally successful against a fully organised effort to create a 
 British industry ; but, on the other hand, nobody can be justified 
 in asserting, as our patent law is understood and administered at 
 the present time, that such a large and organised institution 
 would have any better chance than the resolute manufacturer, like 
 the Levinstein Company in 1883, of making an effective stand 
 against the overwhelming brute force of a judicial injunction. 
 
 (An analysis of defects in the existing patent law, and suggestions 
 for their removal, follow here.} 
 
 Patent right is a privilege of such a character that it would 
 not be impaired for the purposes of beneficent operation by being 
 subject to a larger discretion in the exercise of the power of 
 suspension reserved to the Crown than is provided for in the 
 Patent Act. The objects of the grant are threefold : 
 
 1. The common good and benefit to the realm. 
 
 2. Reward and recompense for the industry, trouble, and 
 charges of the patentee. 
 
 3. The encouragement of other inventors in such laudable 
 and commendable labours as may tend to the good use and 
 service of the realm. 
 
 Now it is obvious, and may be taken to be generally admitted, 
 that such an absolutely unrestricted power of exclusive manu- 
 facture as was conceded in the Badische and Levinstein case 
 tends directly, not to promote, but to subvert the first of these 
 objects. It tends also to produce that just cause of grievance 
 which it was one of the declared objects of the Crown to avoid 
 in connection with the grant. Hence it may be said, with 
 confidence, that the relief by injunction which was granted in 
 the Levinstein case is subversive of the objects of the patent 
 grant itself. The practical question, therefore, is not whether 
 the power to restrain infringement by injunction shall be wholly 
 uncontrolled, but to what extent it should be controlled. The 
 obvious answer to this question is that it ought to be controlled 
 
398 THE BRITISH COAL-TAR INDUSTRY 
 
 to such an extent as to secure all the objects of the grant ; includ- 
 ing the avoidance of any just cause of grievance. An answer 
 in those terms, however, is not very instructive, because the 
 practical difficulty is to discover those rules of practice which will 
 attain the end. One inference may, however, with confidence 
 be drawn even from this extremely indefinite statement of the 
 principle, and it is this : The injunction ought not to go as 
 mere matter of course, and without consideration of the cir- 
 cumstances of the case. A court, when granting an injunction, 
 ought to satisfy itself that the injunction will not cause the 
 inconveniences which followed in the Badische case, and, therefore, 
 something more than mere infringement ought to be established 
 to justify a court in granting a perpetual injunction. 
 
 The general principle with regard to injunctions was thus 
 stated by Lord Brougham : 
 
 " The principle which, as I humbly conceive, ought, generally 
 speaking, to be the guide of the court and to limit its discretion 
 in granting injunctions, at least where no very special circum- 
 stances occur, is that only such restraint shall be imposed as 
 may suffice to stop the mischief complained of." Blackmore v. 
 The Glamorganshire Canal Navigation, i Mylne and Keen, 185. 
 
 Coming to a narrower and, for our present purpose, more 
 pointed statement of the principle, we have it formulated by 
 Lord Lindley in the following terms : 
 
 " The very first principle of injunction law is that prima facie 
 you do not obtain injunctions to restrain actionable wrongs for 
 which damages are the proper remedy." London and Blackwall 
 Ry. v. Cross, Law Rep., 31 Chanc. Div., p. 369. 
 
 The careful observation of this salutary rule would obviously 
 preclude such mischievous results as we are now discussing, 
 and with such authority as it is possible to cite for the rule 
 one may without presumption speak of the existing and 
 mischievous practice as being a lapse from the sound doctrine 
 of the English law. 
 
 Let it be supposed, then, that by some means, either by 
 a voluntary recurrence on the part of the courts to Lord 
 Brougham's rule, or, failing that, by legislation, we were to 
 arrive at a satisfactory settlement of this practice, is there any 
 reason to think that the system would work badly and would 
 unfairly prejudice the rights of a patentee ? For the purpose 
 of discussing this question, I will assume that recourse is had 
 
PATENT LAW REFORM 399 
 
 to Parliament, and that an enactment has been put upon the 
 statute book which goes in one particular beyond the older 
 practice of the Court of Chancery. I will assume, that is to say, 
 that the enactment provides in effect : 
 
 (1) That no perpetual injunction shall in any case be granted 
 to restrain infringement of a patent right, but only an injunction 
 to stand until further order ; 
 
 (2) That no injunction shall be granted to restrain infringe- 
 ment of a patent right unless it is proved to the satisfaction of 
 the court that the mischievous result to the patentee from the 
 infringement proved is such that he cannot obtain adequate 
 relief in respect thereof from the defendant charged with the 
 infringement. 
 
 What would be the result upon patent rights of such a 
 modification of the existing practice of the courts ? 
 
 (1) It would at once put an end to the blackmailing type 
 of patent action. In recent years a practice has grown up of 
 bringing patent actions against perfectly innocent infringers who 
 have no sufficient interest in the dispute to make an effective 
 defence. Now it is clear that if no injunction could be granted, 
 but only damages in a case of that sort, the patentee would find 
 that type of action a very unprofitable investment. 
 
 (2) Again, in a case such as the Badische action, it is clear 
 that the patentees would have been wholly unable to destroy 
 the British industry which they set themselves to attack. In 
 fact, it is probable that the result of that action would in such 
 a case have been more satisfactory to them as well as to the 
 defendant company than in fact it was. If they could not have 
 obtained an injunction they would have had to be content with 
 damages ; and although it may be presumed that in the circum- 
 stances of that case the damages would have been small, they 
 still would have amounted to something. 
 
 The proposal to establish a large manufacturing industry 
 under the existing conditions of the aniline-dye manufacture 
 is one which raises not only the commercial questions of 
 capitalisation and organisation, but also, in a very pressing form, 
 the comparatively dormant question of a reform of the patent 
 law. The comparative backwardness of our manufacture in 
 this line, easily as it is explained by those who allege the 
 indolence, supineness, and inaptitude for this class of industry 
 of the British manufacturer, can nevertheless be fully explained 
 
400 THE BRITISH COAL-TAR INDUSTRY 
 
 only when the pitfalls of our patent law are also taken into 
 account. There is no doubt that both in 1852 and in 1883 
 substantial improvements were introduced into the administra- 
 tion of our patent law. That the Act of 1907 made for 
 improvement is open to much question. It complicated our 
 system by the introduction of incongruous elements, chiefly 
 from the German patent code, but it left untouched the mischiefs 
 which destroyed the British manufacture of aniline dyes, and laid 
 us open to misunderstanding and reprisal in foreign countries 
 without securing any countervailing advantage for our own 
 manufactures and manufacturers. 
 
XXXI. : 1915 
 
 THE SUPPLY OF DYEWARES 
 
 BY PROFESSOR R. MELDOLA, D.Sc., LL.D., F.R.S. 
 
 (Abstract of Presidential Address to the Institute of Chemistry, 
 ist March 1915) 
 
 EARLY in August last year, as appeared from a question raised 
 in the House of Commons, it was foreseen that difficulties might 
 arise in this country, and that certain industries especially those 
 connected with textiles might be seriously affected through the 
 stoppage of supplies of chemical products, more particularly 
 dyestuffs, for which we were dependent to a preponderating 
 extent upon German factories. 
 
 I may be pardoned on the present occasion if I venture to 
 recall a warning which I sounded nearly thirty years ago. As 
 far back as 1886, I foresaw that the coal-tar colour industry as 
 conducted by us was doomed to decadence in this country. 1 
 Systematic inquiries made among the consumers revealed the 
 fact that even at that time 90 per cent, of the dyestuffs then in 
 use here were of foreign manufacture. The voluminous news- 
 paper correspondence which has been going on in connection 
 with this subject all over the country during the last few months 
 shows that, in military parlance, no lost ground has been regained 
 before the outbreak of the war we were still importing nine-tenths 
 of our colouring matters from Germany and Switzerland. Since 
 1886, on every suitable occasion, I have been endeavouring 
 to instil into the public mind the lesson that the development 
 of this industry abroad has been due to the recognition and 
 utilisation by manufacturers of the results of chemical research. 
 To me, therefore, the crisis threatening our textile industries is 
 no matter for surprise it appears simply as a relationship of 
 
 1 See Meldola, Jour. Soc. Arts, 1886. See p. 121, ante. 
 
 401 26 
 
402 THE BRITISH COAL-TAR INDUSTRY 
 
 effect to cause. It is generally supposed that the prophet who, 
 justified by events, is enabled to say " I told you so," is privileged 
 to regard himself with the greatest complacency. In the present 
 case, the only feeling I am able to express is one of humiliation : 
 it is absolutely painful that under the stress of circumstances 
 our weakness should have been laid bare to all the nations a 
 weakness for which there can be found no justification in the 
 plea that no alarm had been raised or that the supply of chemical 
 talent in this country was inadequate. 
 
 The President of the Board of Trade appointed early in 
 August a committee for the purpose of advising the Government 
 with respect to the means of meeting the national requirements, 
 with the Lord Chancellor, Viscount Haldane, as chairman. From 
 this main committee there was subsequently formed a sub-com- 
 mittee for dealing especially with the manufacture of dyestuffs, 
 under the chairmanship of Lord Moulton, whose extensive 
 experience in matters connected with this branch of applied 
 chemistry is well known. 
 
 It is now public knowledge that a scheme formulated by 
 the Government in consultation with a committee representa- 
 tive of the great dye-using organisations was put forward at the 
 close of last year, and after full discussion by those immediately 
 concerned was finally referred back for modification. This is 
 not the occasion for entering into a detailed analysis of the 
 various grounds on which the scheme was considered unsatis- 
 factory, but the Government has determined as I think, wisely 
 not to allow the project to fall through, and has now launched 
 a new scheme which differs from the first in certain important 
 particulars. Whether this new scheme will materialise remains 
 to be seen : so far, all that can be said is that a considerable 
 number of the dye-consuming companies appear to be favourably 
 disposed towards it. It would be out of place here to attempt 
 to explain or to criticise the scheme as it stands, but I want it 
 to be clearly understood, as there has been much public mis- 
 apprehension on this point, that for neither of these schemes is 
 the Board of Trade Advisory Committee or the Dyestuffs Sub- 
 Committee in any way responsible. The grounds on which it 
 was considered that public action was imperatively called for 
 were set forth most clearly in an address delivered by Lord 
 Moulton at Manchester, on 8th December of last year, 1 and in 
 
 1 See p. 351, ante. 
 
THE SUPPLY OF DYEWARES 403 
 
 that address he stated explicitly that he only held himself re- 
 sponsible for the advice that the Government should take action, 
 but not for the particular shape or form which that action should 
 assume. Out of the present situation, therefore, there arise 
 certain general considerations which the chemical profession will 
 do well to take note of, and for this reason I will venture to 
 direct your attention to some of them. 
 
 In the first place, stating the case baldly, and in the broadest 
 possible terms, the principle is adopted that there should be 
 established a company in which the consumers should be the 
 chief shareholders, and which the Government should subsidise 
 by advancing capital at a certain rate of interest to the extent 
 of i, 000,000. It is unnecessary to go into details, but it will 
 be seen that the scheme is in a way a co-operative one and that, 
 for the first time, we have a distinct proposal in this country for 
 the establishment of a State-aided industry. It is beyond our 
 province to discuss this proposal in its economic or political 
 bearings. In view of the great interests at stake, the policy 
 appears to me to be a sound one, as was admitted by both 
 political parties when the proposal was mentioned in the House 
 of Commons last November by the President of the Board of 
 Trade (Times report, 28th November 1914). What concerns 
 us most as representatives of the chemical profession is that our 
 aspect of this great industry should be kept well to the fore in 
 the present scheme, or in any other scheme that may hereafter 
 be put forward. 
 
 In the next place, I take it for granted that we all desire to 
 see the restoration of the coal-tar colour industry to this country, 
 and, be it noted, not only restored, but permanently retained 
 after the war. Now, the discussions of the Government schemes 
 in various parts of the country by dye-consuming organisations, 
 Chambers of Commerce, and so forth, have all centred round 
 political or economic questions ; that which is to us the vital 
 principle, viz. adequate chemical control, has been subordinated 
 or left out of consideration altogether. It is the old, old story 
 we wrangle over the question as to the method by which the 
 industry shall be established and maintained here, whether by 
 Free Trade or Protection, or Subvention or by any other device, 
 and we leave out of consideration the question whether a few 
 years hence there will be anything in the way of dyestuffs worth 
 protecting ; whether there will be a sufficient basis of material 
 
404 THE BRITISH COAL-TAR INDUSTRY 
 
 products left for the politicians and economists and business 
 people to wrangle over. It is not a purely business problem 
 which the Government has undertaken to solve ; it is primarily 
 a chemical problem. It is not even a business problem in the 
 ordinary trade sense, because the main object is at first to supply 
 our own wants, and the chief consumers are to be the chief pro- 
 ducers. The question of business in the sense of export trade 
 is at present remote. 
 
 The conditions which have to be met if we wish to see this 
 country once more the home of the colour industry may be 
 well known to us here, but are certainly imperfectly understood 
 by the public. Even those most concerned those who are 
 invited to subscribe the capital appear in most cases to have 
 an idea that all that is necessary is to find the money, secure 
 the Government aid, appoint a board of business directors, and 
 lo ! the industry will forthwith spring into existence ready to 
 cope with all emergencies. Now, what are the facts of the 
 case ? About five hundred different dyestuffs of definite com- 
 positions have been given to tinctorial industry as the products 
 of chemical research. Of these, a certain number only can be and 
 are being made in this country, the total output of our factories 
 being at present inadequate for the requirements of our textile 
 industries. The first step to be taken, therefore, is to enlarge 
 and develop our existing factories so that the dyes which can 
 be made here should be turned out in larger quantities. This 
 necessity has, of course, been provided for in the Government 
 scheme, and so far so good. Moreover, if the extension of 
 the existing factories still leaves us with insufficient supplies, 
 new factories must be erected and equipped. That also is pro- 
 vided for in the scheme ; but if we want to establish the 
 industry here permanently we must look beyond all this where 
 shall we be left after the war ? We shall be in possession of 
 processes for making a certain number of dyes, and the supply 
 of this particular set of products may possibly be sufficient for 
 the particular purposes for which they are required. Let us 
 label these provisionally " staple products." But there will still 
 be an outstanding number probably a majority of other pro- 
 ducts which we have never yet made here, and for the working 
 out of these processes no combination of " business " talent is 
 of the slightest value. I repeat, it is not a business question, 
 but a chemical question, and it is by chemkal research alone that 
 
THE SUPPLY OF DYEWARES 405 
 
 our colour industry can be saved in the long run. Consider the 
 leeway that we have to make up. The German colour industry 
 has been built up by the utilisation of the results of research 
 carried on in the factories and universities and technical schools 
 for a period of over forty years ! To suppose that we can 
 retrieve our position after forty years of neglect by starting a 
 company the directorate of which is to consist solely of business 
 people is simply ludicrous. It was against this principle that I 
 ventured to raise my voice in the Times of 2Oth January last, and 
 I am extremely glad to find that not only the chemical and 
 technical worlds, but the large and representative body of dye 
 users and producers which form the Dyewares Supply Enquiry 
 Committee of the Society of Dyers and Colourists, fully endorse 
 this view and have forwarded to the Board of Trade a resolution, 
 passed at Manchester last month, in support thereof. A meeting 
 of the Federation of the Light Leather Trades held at the 
 Leathersellers' Hall on 22nd February passed a similar resolution. 
 It is satisfactory to learn that there are at any rate some of the 
 dye-consuming organisations which have grasped the situation 
 scientifically. To imagine that a dyer, however skilful he may 
 be, is, by virtue of his occupation, necessarily competent to 
 direct the affairs of a company which is concerned with the 
 manufacture of the dyes which he uses, is about as sensible as 
 the assumption that a person who can tell the time by his watch 
 is thereby qualified to undertake the direction of a factory for 
 the construction of chronometers. 
 
 One feature of the new scheme which the chemical profession 
 will view with favour is the distinct recognition of research as a 
 necessity for the development of the industry. The Government 
 "will, for ten years, grant not more than 100,000 for ex- 
 perimental and laboratory work." That, although an inadequate 
 endowment, is certainly a concession which marks an advance in 
 official opinion for which we are grateful. It will be for the 
 satirist of the future to point out that it required a European 
 war of unparalleled magnitude to bring about this official recog- 
 nition of the bearing of science upon industry. It would be 
 but a truism to state here the purposes for which research is 
 required ; the question we have to raise is Who is to direct 
 this research ? A directorate of purely business people would 
 certainly be incompetent ; a board composed of dye users could 
 do no more than indicate what dyestuffs were needed. True, it 
 
406 THE BRITISH COAL-TAR INDUSTRY 
 
 is proposed that the company should take powers to secure the 
 assistance of a committee of experts, but this appears to me to 
 be simply a reversion to that policy of " drift " which I have 
 for so long been struggling to overthrow. The experts are, as 
 usual in this country, subordinated ; their assistance is to be 
 invoked at the discretion of a board the members of which can 
 have no real knowledge of the conditions necessary for producing 
 the materials they require now still less would they be com- 
 petent to point out dangers ahead. The "staple products" 
 upon which they are asked to stake their capital may a few years 
 hence be superseded by the products of subsequent discovery. 
 The policy of attempting to run a highly specialised and rapidly 
 developing branch of organic chemical industry by a company 
 of business people, with expert assistance when required, is fatal 
 if we want to establish the industry permanently here. The 
 group of industries which have arisen from the products of the 
 tar-still are not going to remain stagnant after the war, and it 
 is scientific guidance and not mere assistance that will keep them 
 alive. It is the expert, and the expert only, who can foresee 
 the course of development, who can keep in touch with the 
 progress of research, and who can direct with intelligence the 
 campaign against our competitors. If such scientific direction is 
 withheld, all schemes are sooner or later bound to end in failure. 
 
XXXII.: 1915 
 
 THE POSITION OF THE ORGANIC 
 CHEMICAL INDUSTRY 
 
 BY PROFESSOR W. H. PERKIN, F.R.S. 
 
 (Presidential Address delivered to the Chemical Society, 25th March 1915 : 
 Journal of the Chemical Society, 1915, p. 557) 
 
 THE subject which 1 have chosen for my address on this occasion 
 must always be regarded as of the highest importance, not only 
 to this Society, but also to the country at large, because of its 
 intimate connection with the prosperity of so many of our largest 
 and most successful industries. It is a subject which has been 
 discussed over and over again at scientific societies, in scientific 
 journals, and particularly in the newspapers by chemists, manu- 
 facturers, politicians, and the general public. In his valuable 
 presidential address to this Society in 1907, entitled "The 
 Position and Prospects of Chemical Research in Great Britain," 
 Professor Meldola had much to say about the bearing of research 
 on the position of industry ; and in 1909 the same writer dis- 
 cussed very fully the question of the value of education and 
 research in connection with applied chemistry in his presidential 
 address to the Society of Chemical Industry. It would therefore 
 seem scarcely necessary that I should take up your time by 
 bringing these matters to your notice again. I do not propose, 
 however, to apologise, partly because I am of the opinion that a 
 summary of the position of the organic chemical industry in as 
 few words as possible will not be out of place and may be useful, 
 but more particularly because, in spite of the large amount of 
 literature bearing on the subject, I feel convinced that the causes 
 of the decadence of this industry in this country are still imper- 
 fectly understood. 
 
 407 
 
4 o8 THE BRITISH COAL-TAR INDUSTRY 
 
 The seriousness of the position is readily grasped when it is 
 borne in mind that the value of the colouring matters consumed 
 in this country is at least 2,000,000 per annum, and that more 
 than 90 per cent, of this quantity comes from Germany ; and, 
 when it is remembered that these dyes are essential to textile 
 industries representing at least 200,000,000 per annum, and 
 employing more than 1,500,000 workers, it is easy to see to 
 what an alarming extent these great industries are in the grip 
 and power of the Germans. There are, of course, many other 
 industries which depend on colouring matters for their existence, 
 such as, for example, the wallpaper, the printing, and paint 
 industries, to all of which lakes and pigments are absolutely 
 essential, and of late years almost the whole of these have been 
 imported from Germany. Again, the enormous quantities of 
 organic chemicals required for photographic purposes such as, 
 for example, pyrogallic acid, hydroquinone, metol, and many 
 other similar developers, the natural and artificial products 
 employed in such huge quantities in the manufacture of scents 
 and perfumes, the synthetical and other drugs which have in 
 some ways revolutionised medical science, and also many of the 
 more important disinfectants, have been almost exclusively made 
 in Germany. We may add to this list the vast trade in fine 
 chemicals, for here we are again completely outclassed, since 
 there are no firms in this country which can compete with 
 Kahlbaum, Merck, Schering, de Haen, and a host of others 
 either in the range or the purity of their products, and it has 
 long been our habit to import almost all our organic fine 
 chemicals from Germany. It may indeed be said that Germany 
 has no competitor worth considering in the whole domain of 
 organic chemical industry. That we should have allowed trades 
 of such magnitude to pass almost completely into the hands of 
 a foreign nation seems incredible, and, as the inevitable result, 
 we are face to face with the serious position that, the foreign 
 supply having stopped, stocks are rapidly vanishing and prices 
 are rising to such an impossible level that the progress of several 
 of our industries is greatly hampered. Indigo, perhaps the 
 most essential of all dyes, is manufactured entirely by the great 
 German colour works, and the stock in this country a few weeks 
 ago was so low that the price rose to at least ten times what it 
 was before the war ; the same thing is happening in other cases, 
 and many dyes cannot be obtained at any price. Obviously we 
 
THE ORGANIC CHEMICAL INDUSTRY 409 
 
 must take warning, and not allow, in the future, our textile and 
 so many other similar industries to be controlled in this way 
 by the foreigner, and to be in danger of being brought to a 
 standstill. 
 
 How are we to explain the fact that we have allowed some 
 of our most important industries to get into this critical condition, 
 and what do we propose to do to remedy this state of things 
 and prevent any recurrence in the future ? No one doubts for 
 a moment that the wonderful opportunity of establishing a great 
 national industry, due to the discovery of the aniline dyes in 
 this country, has been allowed to escape us, and various reasons 
 have been put forward to explain the loss of the colour industry. 
 There can be no doubt that a good many different causes have 
 been at work. One of the main reasons for our position is that 
 we as a nation, and our manufacturers in particular, have failed 
 to understand the extreme complexity of the scientific basis of 
 organic chemical industry, and have concluded that this industry 
 could be carried on much in the same way as the manufacture 
 of sulphuric acid, caustic soda, and other heavy chemicals. The 
 manufacturer has always been unwilling to acknowledge that 
 neglect of science in his works is the real cause of his failure to 
 retain the colour industry in this country, and has therefore put 
 forward all sorts of other reasons to explain his want of success. 
 
 Thus it has been urged repeatedly that our patent laws were 
 greatly to blame, and that these laws were such that an English 
 patent was no protection, and that so soon as anything new had 
 been discovered in this country the Germans at once set to work 
 to manufacture it. 
 
 Even if this were true and there may be some truth in it 
 it does not explain why the Germans were able to obtain their 
 raw material as they did in this country, to transport it to Ger- 
 many, and then to send the dye over here, and at the same time 
 to make a handsome profit out of the transaction. Again, it has 
 been urged that the obstacles to the use of pure alcohol which 
 existed at the end of the last century played a great part in 
 bringing about the decadence of the coal-tar colour industry in 
 this country. Possibly there has been some hardship in special 
 cases, but a Departmental Committee of the Board of Trade took 
 evidence from a large number of experts in this country and in 
 Germany, and issued a report on " Industrial Alcohol" in 1905, 
 and the Committee arrived at the conclusion that, as a statement 
 
4 io THE BRITISH COAL-TAR INDUSTRY 
 
 of historical fact, the assertion that the coal-tar industry has been 
 lost to this country on account of obstacles to the use of pure 
 alcohol is devoid of substantial foundation. 1 Of late years the 
 restrictions on the use of duty-free alcohol have been so relaxed 
 and the denaturants which may be employed are of such a wide 
 range, including as they do the actual articles to be manufac- 
 tured, 2 that there is probably at the present time less difficulty 
 put in the way of the manufacturer here than is the case in 
 Germany. 
 
 It is quite obvious that other reasons than those I have just 
 mentioned must be found to account for the gradual transference 
 of the coal-tar industry to Germany. The decadence of this 
 industry and its gradual transference to Germany may be said to 
 have begun during the period 1870-75. It was in 1874 that 
 the works of Perkin & Sons at Greenford Green was sold to the 
 firm of Brooke, Simpson & Spiller, and these works were then 
 in the most prosperous condition, and much in advance of any- 
 thing that existed in Germany. 
 
 One reason for the sale was my father's natural dislike to an 
 industrial career, and his desire to devote himself entirely to 
 pure chemistry. There was, however, a much more weighty 
 consideration which played the really important part in his 
 decision to dispose of the works. 
 
 It was recognised and, as the subsequent history of the coal- 
 tar industry has shown, correctly recognised that the works 
 could not be carried on successfully in competition with the rising 
 industry in Germany unless a number of first-rate chemists could 
 be obtained and employed in developing the existing processes, 
 and more particularly in the all-important work of making new 
 discoveries. I remember quite well that inquiries were made at 
 many of the British universities in the hope of discovering young 
 men trained in the methods of organic chemistry, but in vain. 
 There cannot be any doubt that the manufacturer of organic 
 colouring matters during the critical years 1870-80 was, owing 
 to the neglect of organic chemistry by our universities, placed in 
 a very difficult and practically impossible position. At that time 
 organic chemistry was not recognised by the older universities, 
 
 1 See p. 228, ante. 
 
 2 For example, the manufacturer of pure ether may denature the alcohol 
 he uses by the addition of a little sulphuric acid, and, in the case of diethyl- 
 aniline, this substance or aniline may be used as the denaturant, and so on. 
 
THE ORGANIC CHEMICAL INDUSTRY 411 
 
 and the newer universities, which have since done so much for 
 the progress of science, had not come into existence. It is surely 
 remarkable that the study of so important a subject as organic 
 chemistry should not only have been practically ignored by our 
 universities in the past, but that even at the present day it does 
 not flourish in the way it does in almost every university and 
 technical school in Germany. 
 
 This seems to me the more remarkable when it is borne in 
 mind that all problems connected with life, either in the animal 
 or vegetable kingdom, are essentially problems which depend on, 
 and are largely controlled by, organic chemistry, and it is there- 
 fore clear that little progress can be made towards the solution of 
 such problems until the processes of organic chemistry are clearly 
 understood. Quite apart, therefore, from its industrial aspect, 
 organic chemistry must, from the purely scientific point of view, 
 always be regarded as a branch of science of the very highest 
 interest and importance. 
 
 If the record of our universities is examined, it is at once 
 obvious that many of these famous places, and more particularly 
 the universities of Oxford and Cambridge and the Scottish 
 universities, contributed practically nothing to the advancement 
 of organic chemistry during the latter part of the last century, 
 and their output of research in this subject is still far less than it 
 ought to be. It is difficult to understand why our universities 
 should so persistently hold aloof from progress, and should so 
 often entirely fail to gauge the importance of leading the way in 
 new developments, on which, after all, in many cases the welfare 
 of the country depends. How very different is the picture 
 exhibited by the attitude of the German universities towards 
 organic chemistry during the critical period I have mentioned ! 
 
 So soon as the importance of organic chemistry became 
 apparent, great teachers, such as Liebig and Wohler, Kekul6 
 and Baeyer, founded schools specially devoted to the subject, 
 and they and their pupils then began to publish that wonderful 
 series of classical investigations which laid the foundations on 
 which the superstructure has since been raised. 
 
 The value of the example of these great teachers and of the 
 system of research which they had initiated soon became generally 
 appreciated by the universities in Germany, and every effort was 
 made, bv the establishment of laboratories supported by adequate 
 grants from the various States, to help forward the new move- 
 
4 i2 THE BRITISH COAL-TAR INDUSTRY 
 
 ment. The step which, in my opinion, did more than anything 
 else to bring about the wonderful development of organic 
 chemistry in Germany was the provision that research must be 
 an essential part in the training of every German student of 
 chemistry. 
 
 In almost every direction, and to a far greater extent than has 
 been the case in any other country, Germany has recognised the 
 value of the closest possible contact between the industries and 
 the universities. In Germany the majority of the Professors and 
 Privatdocenten are in close touch with the large factories, and 
 spend part of their time in solving technical problems which they 
 either devise themselves or which may be submitted to them by 
 the manufacturer. 
 
 I have it on the authority of several of the best-known 
 directors of German works that the atmosphere of the university 
 laboratory is much more suitable for discovery than that of the 
 works, and that, as a fact, many of the most valuable discoveries 
 which subsequently proved to be of the highest technical im- 
 portance have been made in university laboratories and transferred 
 to the works as the result of the intimate connection I have just 
 described. Moreover, when it is remembered that the important 
 dyes, malachite green, the phthaleins, artificial alizarin, and in- 
 digo, and the pharmaceutical products antifebrin and antipyrine, 
 to mention only a very few cases, were discovered in university 
 chemical laboratories, it is quite clear that there is much truth 
 in the statement of the works directors. Close association of 
 the universities with the industries does not exist to any extent 
 in this country, and is one of the things we have to aim at in 
 the future, however distasteful this may appear to some of our 
 academic circles. Systems of training and methods of teaching 
 which may have been useful centuries ago, but have become 
 antiquated, must, in these days of acute competition, give place 
 to methods that are more in accordance with existing requirements 
 and the practice of other nations ; otherwise we are bound to 
 fall behind in the race. 
 
 It must, I take it, be assumed that the aim of the university 
 is to acquire the best scientific ability for its professoriate and 
 teaching staff, and therefore the home of the best scientific re- 
 search talent must always be the university laboratory ; it is there- 
 fore quite clear that close association between these laboratories 
 and the works must be of great advantage to industry. Such a 
 
THE ORGANIC CHEMICAL INDUSTRY 413 
 
 connection cannot fail to be of great value also to the university, 
 for it must result in the manufacturer taking a keen interest in 
 the welfare of the department with which he is associated ; he 
 will willingly provide material from his works for teaching and 
 research, and subscribe liberally to the resources of the depart- 
 ment, and no scientific laboratory chemical, physical, or 
 engineering can do good work unless it is liberally supplied 
 with material and funds. 
 
 It has often been suggested to me that a professor who is 
 engaged in solving problems of a technical nature will have no 
 time for other scientific research work, and that, since results of 
 technical value must often be kept secret and may never be 
 published, the reputation of his department will suffer. Ex- 
 perience shows, however, that such is not the case, for there 
 is little, if any, diminution in the output of research work in 
 pure science from the German laboratories as the result of this 
 system. 
 
 We must, I think, agree that one of the main reasons for the 
 rise and development of the German chemical works is the 
 appreciation on the part of the manufacturer of the value of 
 science in connection with industry, and the recognition of the 
 great importance of a close alliance between the works and the 
 research laboratories of the universities and leading technical 
 institutions of the country. 
 
 My view is that contact with the research department of a 
 large works must always be stimulating ; problems are en- 
 countered, many of them of great scientific interest, which would 
 never suggest themselves in strictly academic circumstances ; and 
 as one of the results, the tendency, which is always present under 
 existing university conditions, for the professor to become an 
 academic fossil and unproductive is postponed. Again, we are 
 all aware how difficult it often is to find suitable research subjects 
 for the budding chemists under our charge, and contact with the 
 research departments of a flourishing works cannot fail to suggest 
 subjects for investigation which are eminently suitable to occupy 
 the attention of young men, many of whom will ultimately take 
 up technical work. I look forward to the time when the scientific 
 staffs of our universities and technical schools will not only be 
 available for industrial research, but will be encouraged by those 
 in authority to undertake such work ; for 1 am quite certain, 
 and indeed it is very generally admitted, that the association 
 
4H THE BRITISH COAL-TAR INDUSTRY 
 
 of the best academical talent in the country with the technical 
 laboratories of the works can only be of the highest mutual 
 benefit. 
 
 After all, this kind of thing is quite common in the case of 
 the engineering departments of our universities and technical 
 schools ; and if the system works well in the case of engineering, 
 there is surely no reason why it should not be equally successful 
 in the case of chemistry. 
 
 Our competitors have, from time to time, given their opinion 
 as to the reasons for the transference of the organic chemical 
 industry from this country to Germany, and, as such views 
 cannot fail to be instructive, it will not be out of place if I quote 
 one such utterance. On the occasion of the jubilee or the 
 discovery of mauve, in 1905, Dr Duisberg, one of the best- 
 known directors of the colour works of Bayer & Co., in Elberfeld, 
 went fully into this question, and I propose to read a few extracts 
 from his remarks which have a special bearing on this matter. 
 Dr Duisberg said : " You inquire further, and wish to know 
 how it is that the German soil, in which the coal-tar colour 
 industry has grown so powerful, varies from English soil ; what 
 particular conditions were there which had been so advantageous 
 for its fructification ; whether it was not eventually possible to 
 produce artificially the same conditions also in England, and 
 that here also in the land of its birth those rich and golden fruits 
 could not be gathered, the harvest of which is reaped by Germany 
 year by year. I do not believe in such acclimatisation in England, 
 at least for the present. No other industry requires so much 
 uniformity of thought and action, science and practice, as organic 
 chemistry and the organic chemical industry. 
 
 "In Germany, not only has chemical science developed to a 
 considerable extent, but at the same time the technique of organic 
 chemistry has flourished. Both have stimulated and vitalised 
 each other, and both have supported each other. Such was not 
 the case in England. Although the Englishman is in general 
 practical, he is wanting in that peculiar quality which we 
 Germans are remarkable for that is, not perseverance, but 
 patience and the power of waiting for success. For all the 
 Englishman does he expects soon to be compensated in hard 
 cash." 
 
 Continuing, Dr Duisberg used the following words, which 
 are particularly interesting in view of the present crisis : "But 
 
THE ORGANIC CHEMICAL INDUSTRY 415 
 
 you will say, when the problems have been solved, and when the 
 patents have run out and the manufacture is free to everyone, 
 c Why should not the English and foreign works decide to cope 
 with the German firms and compete against them ? ' 
 
 "In my opinion this would be futile, and would be of no 
 avail. Even in Germany, where, as we have seen, the conditions 
 are the most favourable, it would now be scarcely possible, or 
 at least be a singular coincidence if a manufacturer, although 
 possessed of energy and capital, should succeed in building up a 
 new firm in the colour line so as successfully to compete against 
 the existing powerful works. Whereas, therefore, the conditions 
 in England for many industries, such as for the mining industry, 
 for spinning and weaving, not forgetting inorganic chemistry, are 
 far more advantageous than in Germany, the latter country has 
 the natural privilege in the organic chemical industry, and other 
 nations should not envy her in this, but leave it to her." 
 
 It is because we have acted in the manner recommended by 
 Dr Duisberg, and have left the coal-tar colour industry to 
 Germany, that we find ourselves in the present grave and serious 
 position. 
 
 Views similar to those of Dr Duisberg have been expressed 
 in many quarters, and Lord Moulton, speaking at the Royal 
 Society of Arts on 3rd December of last year, gives an example 
 which is also very much to the point. 1 " I read," he said, " the 
 other day with bitter feelings the address of one of the ablest 
 industrial chemists in the world the head of one of the German 
 chemical industries who, talking about this very subject, said : 
 ' England talks not only of holding her own in the war, but of 
 beating us in the chemical industry. She cannot do it, because 
 the nation is incapable of the moral effort of taking up such an 
 industry, which implies study, concentration, patience, and fixing 
 the eye on distant consequences, and not merely on the monetary 
 result.' ' Lord Moulton himself puts the matter in this way : 
 " Some fifty years ago organic chemistry opened up a domain of 
 industrial wealth that he could only compare to that opened up 
 by the discovery of steam power. He had been able to come to 
 but one conclusion that, either from being too well off, or from 
 sluggishness of intellect, or from the fact that the capital of the 
 country had passed into the hands of people who were unwilling 
 either to learn or to think, England had abstained almost entirely 
 
 1 See p. 347, ante. 
 
4 i 6 THE BRITISH COAL-TAR INDUSTRY 
 
 from an attempt to reap the rich harvest open to the industrial 
 world by the advance of organic chemistry." In his address 
 delivered in the Town Hall, Manchester, on 8th December 1914, 
 Lord Moulton said : " Gentlemen, we have to look the truth in 
 the face. It (the loss of the coal-tar colour industry) was for no 
 other reason than that the English dislike study. The English- 
 man is excellent in making the best of the means at his disposal, 
 but he is almost hopeless in one thing. He will not prepare 
 himself by intellectual work for the task that he has to do. Now 
 there is the cause and, so far as is material, the sole cause of the 
 German supremacy. Is that a cause which must permanently 
 operate ? The answer is, of course, ' No.' But it is for us to 
 reform ourselves ; otherwise no relief can come." * 
 
 I have ventured to read these short extracts because they 
 contain the gist of the matter, and because I cannot think of any 
 words which might describe the position better. 
 
 If, then, we accept the enormous technical importance of 
 organic chemistry, and recognise, as Lord Moulton puts it, that 
 the industry is so vast that it can only be compared with that 
 opened up by the discovery of steam power, and if we decide 
 that we are not going to allow as Dr Duisberg suggests that we 
 should all this wealth and prosperity to pass entirely into the 
 hands of a foreign country, what course must our manufacturers 
 adopt in order to get a share of this ? I have already said, and 
 everyone will agree, that they must, in the first place, make up 
 their minds so to conduct their works that research is going on 
 unceasingly ; no works can possibly flourish which is content to 
 manufacture only well-known colours, and it is only by the dis- 
 covery of new colours and other products that manufacturers can 
 hope to get a satisfactory return on their capital. The manu- 
 facturer must therefore see that his laboratories are properly 
 equipped, and well supplied with research chemists of ability, 
 who have had a sound scientific training, and also some ex- 
 perience in the methods of research. All this, however, will 
 avail little unless he has a scientific leader in his works who is 
 able to direct the investigations of his young staff in the right 
 channels. 
 
 Students of mine who have entered chemical works have 
 frequently complained to me that there is no one over them 
 qualified to direct their investigations, and that original work 
 
 1 See p. 351, ante. 
 
THE ORGANIC CHEMICAL INDUSTRY 417 
 
 seems to be considered of secondary importance, and only to be 
 indulged in when there is nothing else in the works to occupy 
 the attention of the chemist. 
 
 So far as I am aware, there is not a single colour works in 
 this country which has a really brilliant scientific head by which 
 I mean a chemist of wide scientific experience, and with the 
 knowledge and ability to direct research ; and this is a very 
 serious state of things, and quite incompatible with chemical 
 efficiency. 
 
 I have long thought that the want of an able scientific head is 
 one of the most obvious reasons why our colour works are in such 
 an unsatisfactory condition. The success of a business based on 
 science must often be essentially the work of a single brilliant 
 scientific man, just as the success of a great school rests with the 
 headmaster, and the reputation of a university laboratory depends 
 on the ability of the professor. 
 
 If a works is fortunate enough to have the services of a 
 distinguished scientific man, capable of initiating and carrying 
 out original investigations, and who will not only be constantly 
 making discoveries himself, but be able at the same time so to 
 influence his young staff that they will follow in his footsteps, 
 the success of such a works can never be in doubt. I am afraid, 
 however, that it will be a long time before we can hope that our 
 manufacturers will give up their old-fashioned rule-of-thumb 
 methods and fully grasp the truth of this vital matter. 
 
 My experience of the manufacturer in this country is that he 
 is usually merely a commercial person who does not like the 
 expert, and especially the idea of giving the expert a prominent 
 position in the control of his works. Possibly the reason in 
 many cases is ignorance of the value of science, but more prob- 
 ably it is due to the fact that, being ignorant of science himself, 
 he feels that if the expert is given too much prominence he 
 must either study himself in order to understand the expert or 
 leave the essential control of the business in his hands. Both 
 these courses are distasteful to the ordinary commercial member 
 of a board of directors ; the expert is therefore relegated to the 
 background, and the business comes to grief. 
 
 It would seem to be scarcely necessary to point out that, if 
 a chemical works is to be successful, the first essential is that it 
 must be under chemical control, and that every department must 
 be in the hands of an expert ; the board of directors may then 
 
 27 
 
4 i 8 THE BRITISH COAL-TAR INDUSTRY 
 
 be a mixed board, provided that steps are taken to ensure that 
 chemical opinion is largely represented on it. The recognition 
 of the soundness of this principle is one of the main reasons for 
 the success of the German works. 
 
 Anyone who has had the opportunity of visiting the principal 
 German colour works, as I have, cannot fail to have noticed that 
 chemical control is everywhere ; the heads of departments are 
 always chemists, and the board of management invariably includes 
 a large proportion of the abler chemical experts employed in the 
 works. Not only do German business men understand that the 
 control of a chemical works must be in the hands of the chemist, 
 but they are also careful to remunerate their chemists liberally 
 and to give them a share in any new development they may 
 initiate, with the result that many of their leading chemists are 
 in receipt of salaries quite unheard of in this country. 
 
 When we ask the question whether we can adopt methods 
 of a similar kind in this country we find ourselves at once face 
 to face with very grave difficulties. Let us assume that the 
 necessity for the chemical control of a chemical works is conceded, 
 as conceded it must be, and that it is clearly understood that the 
 next step is the discovery of improvements in every direction, 
 such as the invention of dyes better than those already known, 
 and the economical development of essential existing processes, 
 then the first thing to be done will be for our universities to set 
 to work to educate a supply of organic research chemists who 
 will be able to undertake this work. This will mean that 
 organic chemistry will have to flourish to a much greater extent 
 than it does now, because the supply of organic research chemists 
 available under ordinary conditions is a very small one, and 
 scarcely sufficient to meet even the moderate demand which exists 
 at the present time. 
 
 If the effort gradually to develop it is not a question of 
 immediately establishing a thriving organic chemical industry 
 in this country is to be seriously taken in hand, and not to be 
 merely talked about, and if the requisite capital is forthcoming, 
 it is obvious that what will be required before everything else will 
 be a really able chemical staff, and there should, therefore, be a 
 great opening in the near future for young organic chemists of 
 ability. It is unfortunate from this point of view that many, 
 probably the large majority, of our young chemists are not 
 immediately available, since most of them are at present engaged 
 
THE ORGANIC CHEMICAL INDUSTRY 419 
 
 in military service, and therefore the evolution of an efficient 
 chemical staff will be no easy matter. A small beginning may 
 have to be made, but, if the manufacturer will continually bear 
 in mind that chemical efficiency must always be the basis of all 
 his calculations, there is no reason to doubt that success will 
 come in the end, even though it may, and probably will, be very 
 slow at first. 
 
 Soon after the outbreak of the war, the critical position brought 
 about by the shortage of the dyes which are vital to both the 
 cotton and wool trades, and the impossibility of importing further 
 supplies from abroad, called for immediate attention. Urgent 
 representations from dyers and calico-printers and others engaged 
 in trades which require large supplies of dyes, forced the Govern- 
 ment to see that something must be done, and done as quickly 
 as possible, to find a solution for the extraordinary situation that 
 had arisen. A Board of Trade Committee was therefore appointed 
 on 25th August, with the Lord High Chancellor (Viscount 
 Haldane) as chairman, 1 with instructions to consider the best 
 means of obtaining for the use of British industry sufficient 
 supplies of chemical products, and, after hearing the evidence 
 of many of the more important producers and consumers, a small 
 committee, of which Professors Meldola and Green and I were 
 members, was charged with the task of sifting the mass of evi- 
 dence which had come forward from all quarters. 
 
 The chairman of this sub-committee Lord Moulton 
 devoted a great amount of his time and energy and experience 
 of German industrial conditions to the task of interviewing repre- 
 sentatives of the industries which were affected by the stoppage 
 of supplies from Germany, and, as the result of the report of the 
 sub-committee to the larger body, a meeting of representatives 
 of industrial firms and associations was held on loth December 
 at the Board of Trade, when the following resolution was passed 
 unanimously : " That this meeting approves in principle of a 
 national effort being made by the trade to increase the British 
 
 1 The other members of the committee were Mr John Anderson, Dr George 
 Thomas Beilby, F.R.S., Prof. James Johnston Dobbie, F.R.S., Mr David 
 Howard, Mr Ivan Levinstein, Prof. Raphael Meldola, F.R.S., Mr Max 
 Muspratt, Prof. William Henry Perkin, F.R.S., Mr Milton S. Sharp, Sir Arthur 
 J. Tedder, Mr Joseph Turner, and Mr Thomas Tyrer, with Mr Frank Gossling, 
 B.Sc., as secretary. Prof. Arthur George Green, M.Sc., was subsequently 
 added to the committee. 
 
420 THE BRITISH COAL-TAR INDUSTRY 
 
 supply of synthetic colours, and welcomes the assistance of His 
 Majesty's Government for that purpose." A committee 1 was 
 appointed, and shortly afterwards recommended a scheme which 
 involved the formation of a joint-stock company, having for its 
 object the manufacture and supply of synthetic colours. Subse- 
 quently the Government announced that they were prepared to 
 assist such an effort in the following way : " If a limited Company 
 were formed on co-operative lines with a share capital of 
 3,000,000, the Government agree to advance to such Company 
 1,500,000, bearing interest at the rate of 4 per cent, per annum, 
 and secured as a first charge on the assets and undertaking of 
 the Company, and to be repayable in twenty-five years." The 
 important proviso was, however, made that " the interest on the 
 advance and a sinking fund for the repayment are to be payable 
 only out of the net profits of the Company, but are to be cumu- 
 lative." When this scheme was made public its reception was 
 not cordial, and the application for shares fell far short of what 
 had evidently been expected by its promoters. In explanation 
 of this it should, in the first place, be quite clearly pointed out 
 that neither the Board of Trade Committee nor the sub-com- 
 mittee had anything whatever to do with the preparation of the 
 scheme, and it is certainly extraordinary that a committee 
 consisting entirely of business men, and which did not include 
 a single chemical expert, should have been entrusted with the 
 formulation of a scheme for the founding and developing of a 
 chemical industry. 2 
 
 Had a chemical expert been present I venture to think that 
 such a scheme would never have been placed before the public. 
 It is stated in the memorandum of agreement attached to the 
 scheme that the Company had been incorporated for the purpose, 
 among other things, of manufacturing and selling dyes, colours, 
 and other chemical substances, which, previously to the war, 
 were exclusively or principally manufactured in Germany, and 
 no mention is made of what ought to be the main object of such 
 a Company, namely, the employment of a large staff of research 
 
 1 The committee appointed was Messrs Lennox Lee (Calico-Printers' 
 Association), Milton S. Sharp (Bradford Dyers' Association), H. W. Christie 
 (United Turkey-Red Company), Chas. Diamond (English Sewing-Cotton 
 Company), G. Marchetti (John Crossley & Sons), and R. D. Pullar (J. 
 Pullar & Sons). 
 
 2 Compare Prof. Meldola's admirable letter in the Times of loth January. 
 
THE ORGANIC CHEMICAL INDUSTRY 421 
 
 chemists under leaders of ability for the purpose of making new 
 discoveries in every possible direction. 
 
 It cannot be too strongly emphasised that it is not merely a 
 question of producing the dyes which are required during the 
 war ; any company which is formed must be established in so 
 strong a position that it can expect to deal successfully with the 
 keen competition which will be waged with the greatest severity 
 by the Germans after the war. 
 
 The promoters of the scheme do not appear to have appreciated 
 the difficulties of the situation, and obviously think that the 
 manufacture of dyes in this country which previous to the war 
 had been invented and produced in Germany is a matter which 
 can quite easily be managed. 
 
 It seems to be imagined in many quarters that, in order to 
 manufacture a dye which had previously been made in Germany, 
 all that is necessary is to follow the directions given in the patent 
 dealing with that particular dye. No greater mistake could 
 possibly be made. It is common knowledge that German manu- 
 facturers have for many years devoted large sums to the estab- 
 lishment of an efficient staff of patent experts, whose business it 
 is so to word a patent that, whilst it satisfies the requirements 
 of the patent laws of the various countries in which it is taken 
 out, only gives such information as is absolutely necessary, and 
 contains no indication of the process which is used in the actual 
 manufacture. In many cases patents are devised which are of no 
 practical value, and are merely intended to mislead and throw 
 competitors on the wrong scent. 1 The discovery of the most 
 efficient method of working patented processes is therefore often 
 a matter of great experimental difficulty, and may require many 
 months of research. Any new Company started with the object 
 of manufacturing dyes which previously to the war had been 
 made exclusively in Germany must therefore be prepared to 
 employ a large staff of research chemists for a long period without 
 any prospect of return in the way of dividends. 
 
 Further, it must always be remembered that the Germans 
 have many years' start of the new Company, and have accumu- 
 lated such vast experience of methods of manufacture, and more 
 particularly of the recovery and economical use of by-products, 
 that they are able to sell at a profit at very low prices. What 
 
 1 This point is well dealt with by Prof. Jocelyn Thorpe, F.R.S., in a letter 
 to the Times of 2nd February. 
 
422 THE BRITISH COAL-TAR INDUSTRY 
 
 the new Company has to face is, therefore, in the first place, the 
 problem of working out methods of manufacture and the utilisa- 
 tion of by-products until they have arrived at the same state of 
 efficiency as the Germans, and that, it seems to me, may be a 
 matter of years. While this is being done, the new Company 
 must also be busily engaged in training a large body of research 
 chemists under the supervision of capable scientific leaders, so 
 that the works may develop in as many new directions as possible, 
 because the Company can only hope for permanent success if it 
 pursues a policy of discovery and invention. Another point has 
 also to be borne in mind, and that is that the Germans supply 
 dyes and other products, not only to this country, but to practi- 
 cally all the other nations, and, in the event of a new Company 
 being formed on such large lines that it might prove to be a 
 serious competitor, a German works could well afford to sell at 
 cost price or at a loss in this country and make its profits in other 
 lands until the new Company had been ruined. Lastly, if we 
 are to be allowed to make dyes, etc., during the war according 
 to patents belonging to the Germans, what is to happen after the 
 war ? Will the Company be still allowed to use these patented 
 processes, or will the patents again become the sole property of 
 the Germans, and be workable in this country only on the 
 payment of royalties or licences ? This matter has, no doubt, 
 been carefully considered by the law advisers of the Government, 
 but, so far as I know, no authoritative statement has been issued 
 which makes this situation clear. 1 
 
 1 Mr Runciman made the following reference to this important point in 
 Parliament on 23rd February last : 
 
 " The success of the concern would depend largely on the way in which the 
 German patents were administered. The Act passed last autumn as an 
 emergency measure provided that the operators of German patents in this 
 country should have a full chance of conducting them under licence, and it was 
 the intention of the Government not to cripple this Company when the war was 
 over, but to give them every opportunity of making the most of German patents. 
 They would leave over for discussion as between Germany and this country the 
 payment of royalty in respect of these patents. There were English patents in 
 Germany on which he hoped a royalty was being paid there. We should hand 
 over these royalties if Germany would bargain fairly with us. But the operating 
 of these patents which would be undertaken by the new Company would pro- 
 ceed after the war was over, without interruption and without hindrance." 
 
 If this statement means that, besides the arduous task of competing with 
 the well-established German works, the new Company may also have to pay 
 royalties or licences to those works, then it is obvious that the difficulties of 
 the situation will be greatly accentuated. 
 
THE ORGANIC CHEMICAL INDUSTRY 423 
 
 Although it is a matter of so much congratulation that the 
 Government, which in past years has paid practically no attention 
 to science and the application of science to industry, should, at 
 last, have recognised the necessity for intervening and in no 
 uncertain fashion, I have been forced to the conclusion, largely 
 for the reasons which I have just stated, that the Company 
 founded on the lines of this first Government scheme could not 
 be expected to be successful in achieving the object which we all 
 have so much at heart, namely, the recovery and development of 
 the organic chemical industry in this country. Since the applica- 
 tion for shares in the proposed Company was quite insufficient, 
 the Government withdrew the scheme, and substituted for it an 
 amended proposal, which is certainly in some respects an im- 
 provement. 1 The new proposal is to form a Company with a 
 share capital of only 2,000,000, towards which the Govern- 
 ment will make a loan for twenty-five years, corresponding with 
 the amount of the share capital raised, and up to a total of 
 1,000,000. 
 
 In addition, and with the desire to promote research, the 
 Government have undertaken for a period of ten years to make 
 a grant to the Company, for the purposes of experimental and 
 laboratory work, up to an amount not exceeding in the aggregate 
 100,000. 
 
 This amended proposal is another proof of the determination 
 of the Government to meet the criticisms which were raised 
 against the first scheme in a generous spirit, and to do all it 
 possibly can to assist the efforts of the manufacturers in this 
 country to place the organic chemical industry on a firm basis. 
 If, then, I make certain criticisms of the new proposal, it must be 
 clearly understood that I do not do so in any spirit of hostility 
 to the scheme, but rather in the hope that the adoption of some 
 modifications in the proposals may make the scheme workable 
 and more likely of success. In the first place I hold that the 
 scheme must be considered in the light of the criticisms which 
 I have just advanced in connection with the first Government 
 
 1 The members of the enlarged Committee which is responsible for the 
 second scheme are Sir A. F. Firth, Bart., Sir Frank Hollins, Bart, Sir Mark 
 Oldroyd, Mr H. W. Christie, Mr J. Clarkson, Mr Charles Diamond, Mr 
 Kenneth Lee, Mr G. Marchetti, and Mr R. D. Pullar ; and, in spite of Prof. 
 Meldola's letter and other letters to the Press, again did not include expert 
 chemical opinion. 
 
4 2 4 THE BRITISH COAL-TAR INDUSTRY 
 
 plan, and I hope that these points will be clearly handled in any 
 detailed statement of this or any subsequent scheme. 
 
 There are, however, other matters which call for comment. 
 The grant for scientific research may be welcomed as a satis- 
 factory addition to the old proposal, mainly because it shows 
 that the Committee of users of dyes have at last found out 
 that research is necessary if the new Company is to be a suc- 
 cess. My own feeling, however, is that the Company ought 
 to provide for research out of its ordinary capital as a matter 
 of course, and should not require a special subsidy for this 
 purpose. 
 
 A much better plan, I venture to think, would be to employ 
 this grant to subsidise the research laboratories of those universi- 
 ties and technical schools which are willing to specialise in organic 
 chemistry, and are prepared to train a certain number of research 
 students with the definite view of their subsequently entering the 
 service of the new Company. Supposing the new Company 
 were to adopt the view which I have urged in this address, that 
 closer connection between the universities and the industries is 
 most desirable, and were to work in conjunction with the staffs 
 of some of the leading organic schools, it is quite obvious that 
 the knowledge of the needs of the works which would result 
 from this connection would enable the staff to supply research 
 students of exactly the type required by the works. Such 
 research students would have been trained under the best 
 scientific supervision which the country can provide, and at the 
 same time they would enter the works with a considerable 
 knowledge of the application of organic chemistry to technical 
 operations, and be in a position to tackle with success research 
 problems connected with new discoveries and new developments 
 in the works. The plan of training research students under 
 these conditions is, as I have already pointed out, the one which 
 has long been adopted with such extraordinary success in 
 Germany, and the large subsidies which the various States place 
 at the disposal of their universities allow of the purchase of 
 expensive apparatus and appliances which are outside the in- 
 adequate resources of most of the university laboratories of 
 this country. 
 
 With regard to the kind of works it is proposed to organise 
 for the manufacture of dyestuffs, etc., which previous to the war 
 had been made in Germany, it would be well carefully to consider 
 
THE ORGANIC CHEMICAL INDUSTRY 425 
 
 the policy which the Germans have adopted with so much success 
 in the matter of the construction and arrangement of their works. 
 I think that one of the things which must strike a visitor to a 
 great German works more perhaps than any other is the order 
 and cleanliness which reigns everywhere, and the obvious care 
 which is taken that every manufacturing operation shall be 
 efficient in every detail. This order and cleanliness is not con- 
 fined to the section of the works which deals with organic pro- 
 ducts ; the same state of things is to be observed in every part, 
 as, for example, in the case of the large plants which deal with 
 the manufacture of sulphuric acid, nitric acid, and other inorganic 
 products. Perhaps the idea which is conveyed most vividly by 
 works such as these, all of which are concerned with the manu- 
 facture of a very large number of products of widely differ- 
 ent character, is that they are, after all, merely laboratories on a 
 larger scale. 
 
 A very different impression is got by an inspection of many 
 of the colour works in this country, and it seems to me very 
 doubtful policy to suggest the possibility of the acquisition of 
 works of this kind, which are obviously not efficient, and could 
 only be made so by pulling down and re-building. It may be 
 said that the most efficient only will be taken over, but selection 
 will be found most difficult, because, if the new Company proves 
 a success, great pressure will be exerted by existing works in 
 order to enter the charmed circle, and the argument of unfair 
 competition will be used for all it is worth, and will be very 
 difficult to deal with. Again, it is most important not to lose 
 sight of the fact that the experience of the Germans is all in 
 favour of building up very large works, and against spreading 
 manufacturing operations over small works situated in different 
 parts of the country. 
 
 The reason for this is obvious. In the manufacture of any 
 substance, by-products are almost always produced which must 
 either be recovered or used in the manufacture of other saleable 
 products ; otherwise serious loss is inevitable. It is exactly in 
 this respect that the Germans are so efficient, and the wonderful 
 organisation which enables them to dovetail one process into 
 another is one of the reasons why the comparatively small works 
 in this country find it impossible to compete with them even in 
 the manufacture of such simple substances as salicylic acid or 
 /3-naphthol. In order that by-products may be used to the best 
 
426 THE BRITISH COAL-TAR INDUSTRY 
 
 advantage it is obviously essential that all these dovetailing 
 operations must be carried out on the same site, so that it may 
 not be necessary to transport the by-products from one works to 
 another, an operation which could not fail to entail loss. Prob- 
 ably the best course for the new Company is either greatly to 
 enlarge the works of Messrs Read Holliday & Sons, or, if it is 
 difficult to find space for this purpose in Huddersfield, to take 
 steps to acquire a suitable site and erect and equip works thereon, 
 a plan which is mentioned in the explanatory statement as one of 
 the objects of the new Company. 
 
 Let us suppose that, in the near future, a practically new 
 works is built on a large scale, and with all the most modern 
 appliances, and that the control of the whole works and of the 
 different departments is placed in the hands of efficient chemical 
 leaders with adequate staffs of chemists under their charge, and 
 that the Company has also large and well-equipped research 
 laboratories busily engaged in discovering new developments and 
 improvements on existing processes ; what prospect has such a 
 works of competing successfully with the existing German 
 organisations and of obtaining a fair share of the organic chemical 
 industry ? 
 
 In answering this important question it must again be empha- 
 sised that the German works with which the new Company must 
 compete are enormous organisations controlling almost unlimited 
 resources and in a most flourishing condition. 
 
 The Farbwerke, vormals Meister, Lucius & Brtining, in 
 H5chst, employs, for example, 350 chemists, 150 engineers and 
 technical experts, 600 clerks, and about 10,000 workmen. The 
 probability of successfully competing with several organisations 
 of this kind, grouped, as they are, in combines in order the more 
 readily to be able to crush competitors and secure the monopoly 
 of the industry, also depends, no doubt, to a great extent on the 
 condition of the German chemical industries after the war. If 
 we suppose that the German companies will continue to work 
 with the same efficiency as before, or will rapidly regain that 
 efficiency, I am inclined to think that we must be prepared to 
 face the certainty that some years must elapse before we can 
 compete successfully against organisations which have taken 
 years to develop and bring to perfection. 
 
 Failure to develop on research lines is scarcely conceivable 
 if the works is in charge of a highly trained chemical staff, but, 
 
THE ORGANIC CHEMICAL INDUSTRY 427 
 
 on the other hand, if it gets into the power of the business man 
 who wants an immediate return for his outlay, is not willing to 
 wait for results, and fails to appreciate the importance of scientific 
 control, then no tariff can avert disaster. I am sure we shall all 
 watch the course of events with the greatest interest, and hope 
 that the new venture may have a large measure of success, and 
 bring back to this country at least a tithe of the prosperity which 
 attaches to the organic chemical industry. 
 
INDEX OF NAMES 
 
 Abel, F. A., 59, 75, 144, 158. 
 Allhusen, C., 317. 
 Anderson, 51, 52, 53,91,236. 
 Anderson, J., 419. 
 Arkwright, 284. 
 
 Armstrong, H. E., 69, 191, 192, 194, 
 221, 222. 
 
 Babbage, 284. 
 
 Badische Anilin- und Soda-Fabrik, 74, 
 85, 94, 97, 119, 136, 190, 196, 198, 
 199, 202, 205, 207, 208, 210, 219, 
 220, 247, 248, 255, 257, 272, 301, 
 308, 312, 320, 326, 327, 365, 368, 
 382, 390. 
 
 Baeyer, A., 50, 53, 74, 95, 97, 98, 122, 
 123, 200, 204, 205, 207, 263, 264, 
 265,272,315, 324,411. 
 
 Bardy, 173, 174. 
 
 Barlow, T., 148. 
 
 Barnes, W. C., & Co., 135. 
 
 Bayer, F., & Co., 198, 210, 224,225,414. 
 
 Beaconsfield, Lord, 190. 
 
 Beale, 241. 
 
 Bechamp, 9, 77, I53> 238. 
 
 Beilby, G. T., 419. 
 
 Beilstein, 169. 
 
 Berlin Aniline Co., 198, 301. 
 
 Bernthsen, A., 102, 131, 193, 224, 325. 
 
 Berry, A. E., 331. 
 
 Berthelot, 51, 52. 
 
 Berzelius, 315. 
 
 Bessemer, H., 284. 
 
 Besthorn, 127, 129. 
 
 Bethels Tar Works, 146. 
 
 Bindschedler & Busch, 365, 366. 
 
 Bindschedler, H., 366, 367. 
 
 Birkeland, 381. 
 
 Black, J., & Co., 78, 134- 
 
 Bloxam, A. G., 269, 279. 
 
 Boettger, 382. 
 
 Bottiger, 192. 
 
 Bowrey, J. J., 145- 
 
 Boyle, R., 284. 
 
 Bradford Dyers' Association, 197. 
 
 Brandenburg, 63. 
 
 Bretonniere, 194, 265. 
 
 British Alizarin Co., 135, 229, 290, 311, 
 312. 
 
 British Cotton and Wool Dyers' Associa- 
 tion, 197. 
 
 Brooke, Simpson & Spiller, 64, 126, 198, 
 237,250,303,410. 
 
 Brougham, Lord, 398. 
 
 Brown, J. T., 145. 
 
 Brunck, H., 204, 219, 221, 324, 326. 
 
 Brunner, J. T., 63. 
 
 Brunner, Mond & Co., 388. 
 
 Bunsen, R., 146. 
 
 Burt, Bolton & Heywood, 56, 117, 250. 
 
 Burwell, 219. 
 
 Cahours, 85, 147. 
 
 Cain, J. C., 243, 278, 294, 297. 
 
 Calvert, C., 33. 
 
 Caro, H., 12, 52, 58, 63, 74, 86, 89, 91, 
 95, 98, 99, H5, 122, 123, 125, 130, 
 136, 148, 154, 168, 170, 178, 184, 
 206, 242, 243, 246, 247, 248, 249, 
 253, 255, 257, 262, 263, 264, 271, 
 3oi, 303, 3i6, 324. 
 
 Cartwright, 284. 
 
 Cassal, C. E., 333. 
 
 Cassella, L., & Co., 196, 198. 
 
 Chapman, A. C., 330. 
 
 Chapman, E. T., 61. 
 
 Chapman, Messel & Co., 250, 255. 
 
 Chapman, S., 190. 
 
 Chapoteaut, 163. 
 
 Chardonnet, Count, 382. 
 
 Chemische Fabrik Griesheim-Elektron, 
 214. 
 
 Cherpin, 29, 171. 
 
 Christie, H. W., 420, 423. 
 
 Church, A. H., 33, 35, 99, 147, 150. 
 
 Clarkson, J., 423. 
 
 Glaus, 129. 
 
 Claus & R^e, 198. 
 
 429 
 
430 
 
 THE BRITISH COAL-TAR INDUSTRY 
 
 Clayton Aniline Co., 198. 
 Cliff, 146. 
 Clowes, F., 145. 
 Coblentz, 242. 
 Coke, Lord, 392. 
 Coleman, J. B., 301. 
 Colin, 48, 53. 
 Collas, in. 
 Coupler, 122. 
 Cox Bros., 133. 
 Crace-Calvert, 254. 
 Croissant, 194, 265. 
 Crookes, W., 145. 
 Crum, Walter, & Co , 134. 
 
 Dale, J., 12, 52, 81, 99, no, 154, 170, 
 
 242, 301. 
 
 Dalmonach Print Works, 155. 
 Dalton, 284, 315. 
 Darwin, F., 284. 
 Davy, H., 284, 3I5- 
 Davy, J., 89. 
 
 Dawson, Dan, & Co., 301. 
 Deacon, 214. 
 Deering, W. H., 145. 
 De Laire, 82, 84, 122, 159, 161, 163,243, 
 
 253- 
 
 De .a Rue, 158. 
 De"pouilly, P. E., 37, 241. 
 Dewar, J., 118, 129, 138, 222, 284. 
 Diamond, C., 420, 423. 
 Diesbach, 380. 
 Divers, E., 145. 
 Dobbie, J. J., 330, 419. 
 Dobereiner, 29. 
 Doebner, O., 63, 85, 262. 
 Dower, 254. 
 Dreaper, W. P., 279. 
 Drewsen, W., 207, 264. 
 Duisberg, C., 282, 289, 292, 294, 325, 414, 
 
 415,416. 
 
 Dumas, A., 53, 91, 142, 146, 164, 236, 315. 
 Duprey, F., 174. 
 Dusart, 178. 
 
 Emmerling, 205. 
 
 Engler, 205. 
 
 English Sewing Cotton Co., 197. 
 
 Ewer & Pick, 131. 
 
 Eyde, 381. 
 
 Faraday, M., 5, 47, 53, 79, 109, no, 123, 
 
 141, 186, 235, 284. 
 Farbenfabriken Elberfeld (see F. Bayer 
 
 & Co.). 
 
 Farbwerke Hoechst (see Meister, Lucius 
 
 & Briining). 
 Feilmann, E., 279. 
 Fichte, 346. 
 Field, F., 32. 
 Filehne, 118, 119. 
 Firth, A. F., 423. 
 Fischer, E., 60, 85, 86, 119, 125, 193,262, 
 
 315, 320, 321, 324, 367, 370. 
 Fischer, O., 60, 84, 85, 86, 11 8, 125, 126, 
 
 127, 129, 262, 265, 324, 367. 
 Fluerscheim, 382. 
 Forster, M. O., 348. 
 Foster, H. A., 310. 
 Franc Bros., 241. 
 Frankland, P., 379. 
 Friswell, R. J., 60, 69, 138. 
 Fritsche, 4, 142, 187. 
 
 Gallik, 97. 
 
 Garden, 142, 235. 
 
 Gardner, W. M., 314, 371. 
 
 Gay-Lussac, 315. 
 
 Gessert Freres, 57, 255. 
 
 Geyger, A., 170, 175. 
 
 Gilliard, Monnet & Cartier, 207. 
 
 Girard, C. H., 82, 84, 122, 159, 161, 171, 
 
 243, 253- 
 
 Girard and De Laire, 21, 22, 163. 
 Glaser, 325. 
 Gordon, J. W., 389. 
 Gossage, W., 317. 
 Gossling, F., 419. 
 Graebe, C., 46, 50, 52, 53, 56, 57, 63, 69, 
 
 91, 93, in, 122, 130, 177, 178, 
 
 179, 183, 205, 245, 246, 247, 248, 
 
 250, 262, 271, 302, 324. 
 Graham, C., 70, 284. 
 Grassier, F., 122. 
 
 Green, A. G., 189, 294, 323, 331, 419. 
 Greenford Green Works (see Perkin 
 
 & Sons). 
 
 Grey, M., 40, 155. 
 Gness, P., 65, 69, 99, 115, 148, 167, 168, 
 
 170, 254, 271, 301, 324. 
 Gnmaux, 85. 
 Guinon, Marnas & Bonnet, 35, 80, 83, 
 
 154. 
 Guyot, 242. 
 
 Haber, 320, 382. 
 Haen, de, 408. 
 Haessermann, 382. 
 Haldane, Lord, 402, 419. 
 Hall, T., 144, 145. 
 Hanhart, 42. 
 
INDEX OF NAMES 
 
 43 
 
 Harrmann, 120. 
 
 Harvey, A., & Son, 133. 
 
 Henderson, 222, 340. 
 
 Hepp, E., 193, 265. 
 
 Heumann, K., 210, 211, 272. 
 
 Heys, Z., & Sons, 134. 
 
 Hickson, E., 132, 313. 
 
 Higgin, 49. 
 
 Hobrecker, 172. 
 
 Hoff, R., 178. 
 
 Hofmann, A. W., 4, 6, 17, 20, 21, 23, 25, 
 26, 27, 44, 45, 80, 81, 86, 100, 108, 
 1 10, 126, 130, 142, 143, 145, 156, 
 1 5%) J 59 5 J 6o, 162, 164, 166, 167, 
 169, 170, 171, 172, 174, 175, 176, 
 177, 1 86, 187, 201, 211, 235, 236, 
 
 242, 246, 253, 254, 262, 278, 300, 
 301, 302, 316, 321, 324, 390. 
 
 Hollins, F., 423. 
 Holzmann, 167. 
 Hoogewerff, 211. 
 Howard, D., 419. 
 Huxley, T. H., 284. 
 
 Jacobson, E., 176. 
 Julius, P., 170. 
 
 Kahlbaum, 408. 
 
 Kalle & Co., 208. 
 
 Kay, 242. 
 
 Kehrmann, 193. 
 
 Keisser, J., 170. 
 
 Keith, T., & Sons, 78, 152, 240, 300. 
 
 Kekule, 50, 51, 53, 178, 185, 261, 262, 
 
 268, 322, 324, 411. 
 Kelvin, Lord, 284. 
 Kern, A., 89. 
 Kirkham, 241. 
 Knietsch, R., 213, 215. 
 Knorr, L., 119. 
 Koch, J. J., 94, 249. 
 Koechlin, H., 117, 118, 123. 
 Kolbe, 34, 83. 
 Kopp, E., 28, 164, 165. 
 Korner, G., 129. 
 Kostanecki, 193. 
 Kiihlberg, 169. 
 
 Laubenheimer, 325. 
 
 Laurent, 37, 51, 53, 65, 91, 142, 146, 236. 
 
 Lauth, C, 29, 61, 84, 85, 171, 172, 241, 
 
 244, 260, 262, 264. 
 Le Bel, 31 5. 
 Le Blanc, 380. 
 Leckie & MacGregor, 133. 
 Lee, K., 423. 
 
 Lee, L., 420. 
 
 Lefevre, 195. 
 
 Leibius, 167. 
 
 Leigh, J., 1 10. 
 
 Leonhardt, A., & Co., 198. 
 
 Levinstein, H., 220. 
 
 Levinstein, I., 117, 135, 200, 203, 275. 
 
 Levinstein Ltd., 198, 390, 419. 
 
 Liebermann, C., 46, 50, 52, 53, 56, 57,91, 
 93, in, 122, 177, 178, 183, 193, 
 205, 245, 246, 247, 248, 250, 271, 
 302, 324. 
 
 Liebig, 29, 109, 1 10, 315, 411. 
 
 Liggins, 140. 
 
 Lightfoot, J., 254. 
 
 Limpricht, 85. 
 
 Linde, C., 381. 
 
 Lowe, 254. 
 
 Luynes, de, 24. 
 
 Macara, C. W., 288, 377. 
 
 M'Kendrick, 118. 
 
 M'Leod, 162. 
 
 Mansfield, C. B., 6, in, 123, 142, 158, 
 
 187, 235, 236, 237, 242. 
 Manson & Henry, 133. 
 Marchetti, G., 420, 423. 
 Martius, 35, 117, 169, 174, 253, 301. 
 Maule, 253. 
 
 Maw, H. W., 350. 
 
 Medlock, H., 18, 82, 121, 124, 157, 158, 
 
 243, 253, 301. 
 Meister, Lucius & Briining, 68, 126, 136, 
 
 198, 205 208, 308, 312, 365, 368, 
 
 370, 426. 
 Meldola, R., 64, 65, 68, 70, 121, 140, 
 
 1 88, 191, 219, 220, 227, 228, 233, 
 234, 257, 259, 284, 294, 322, 323, 
 401, 406, 419, 420, 423. 
 
 Mene, 99. 
 
 Merck, E., 408. 
 
 Messel, R., 190, 255, 348, 350. 
 
 Michaud, 381. 
 
 Michler, 89, 90. 
 
 Miller & Co., 153, 236. 
 
 Mitchell, W. A., 135. 
 
 Mitscherlich, E., 7, 65, 77, 109, no, in, 
 
 142, 187,315. 
 Mond, L., 388. 
 Monnet and Drury, 159. 
 Mortimer, 144. 
 Moulton, Lord, 345, 347, 351, 371, 402, 
 
 415,416,419. 
 Miiller, H., 21, 34, 248. 
 Mundella, 389. 
 Musprat, 142. 
 Musprat, M., 419. 
 
432 THE BRITISH COAL-TAR INDUSTRY 
 
 Natanson, 17, 159. 
 
 Newlands, J. A., 145. 
 
 Newton, J., & Son, 132. 
 
 Nicholson, E. C., 21, 24, 64, 82, 86, 99, 
 121, 124, 126, 157, 158, 160, 161, 
 163, 187, 201, 237, 238, 253, 279, 
 301. 
 
 Nietzki, R., 80, 81, 194, 204. 
 
 Nobel, A., 382. 
 
 Ogilvie, F. G., 349- 
 Oldham, G. W., & Co., 132. 
 Oldroyd, M., 423. 
 Ormandy, W. R., 335. 
 Orr-Ewing, John, & Co., 134. 
 
 Page, F. J. M., 145. 
 Paquier, 381. 
 Peachey, 315. 
 Pedler, A., 145. 
 Peligot, 1 10. 
 
 Perkin, F. M., 221, 298, 321, 336. 
 Perkin, T. D., 150, 243. 
 Perkin, W. H., I, 46, 52, 54, 69, 75, "i, 
 118, 120, 121, 124, 125, 136, 141, 
 
 145, 201, 232, 233, 234, 236, 237, 
 238, 239, 240, 241, 242, 243, 244, 
 246, 247, 248, 249, 250, 251, 252, 
 254, 255, 257, 259, 260, 265, 269, 
 270, 284, 294, 298, 301, 302, 316, 
 321, 384, 390. 
 
 Perkin, W. H., Jim., 407, 419. 
 
 Perkin & Sons, 152, 229, 237, 238, 239, 
 
 240, 243, 250, 251, 253, 254, 260, 
 
 300, 301, 303, 410. 
 Persoz, J., 24, 34, 35. 
 Phillips, C., 242. 
 Poirrier & Chapat, 28, 61, 84, 115, 173, 
 
 260. 
 
 Pope, W.J., 315- 
 
 Price, A. P., 82, 242. 
 
 Price, D., 157, 158,301. 
 
 Priestley, 284. 
 
 Pullar, R., 39, 124, 132, 152, 154, 234, 
 
 240, 241, 298. . 
 
 Pullar, R., & Son, 150, 152, 236, 240, 
 
 241, 298. 
 Pullar, R. D., 420, 423. 
 
 Ramsay, W., 284, 328. 
 
 Rawson, C., 221. 
 
 Read Holliday & Sons, 193, 243, 301, 
 
 426. 
 
 Reichenbach, 176. 
 Reid, W. F., 332, 349- 
 
 Renard Freres, 17, 156, 159, 270, 316. 
 Ripley, E., & Son, 132. 
 Roberts, A., 349. 
 Roberts, Dale & Co., 253, 301. 
 Robiquet, 48, 53. 
 Roemer, 93, 183. 
 Roscoe, H. E., 46, 71, 106, 365. 
 Roussin, Z., 115, 118, 169. 
 Royle, T., 135. 
 Rudolph, C., 126. 
 Runciman, W., 422. 
 
 Runge, F., 4, 15, 34, 79, 142, 186, 235, 
 236. 
 
 Salvetat, 24. 
 
 Samuelson, B., 389. 
 
 Sapper, E., 213. 
 
 Schering, 408. 
 
 Scheurer-Kestner, 241. 
 
 Schiendl, 169. 
 
 Schimmel & Co., 325. 
 
 Schmitt, R., 34, 83. 
 
 Schoenbein, 382. 
 
 Schorlemmer, 52, 81, 254. 
 
 Schultz, A., 40, 155, 163, 240. 
 
 Schultz, G., 286. 
 
 Schunck, E., 48, 49, 53, 91, 93, 183. 
 
 Seidel, P., 215. 
 
 Sharp, M. S., 419, 420. 
 
 Simon-Carves, 108. 
 
 Simpson, Maule & Nicholson, 77, 82, 
 
 122, 126, 157, 158, 161,237, 238, 
 
 242, 243, 253, 301, 303. 
 Singer, I., 280, 294. 
 Skraup, 119. 
 Smiles, 215. 
 Smith, 242, 301. 
 Sobrero, 382. 
 Soci6te des Usines du Rhone (see 
 
 Gilliard, Monnet & Cartier). 
 Spiller, J., 69, 145. 
 Spiller, W., 237, 238, 243. 
 Starck, J. D., 242, 255, 256. 
 St Claire Deville, 148. 
 Stephenson, R., 284. 
 Stevenson, J., & Co., 133. 
 Stirling, W., & Sons, 134. 
 Strecker, 53. 
 
 Tabourin, 241. 
 Tedder, A. V., 419. 
 Templeton, J., & Co., 133. 
 Thenard, P., 147. 
 Thomas, E., 254. 
 Thompson, W. P., 198. 
 Thorp, W., 145. 
 
INDEX OF NAMES 
 
 433 
 
 Thorpe, J., 421. 
 
 Tiemann, 120. 
 
 Tilden, W. A., 315,347, 348. 
 
 Turkey-Red Dyers' Association, 305, 
 
 312. 
 
 Turner, J., 419. 
 Tyndall, 284. 
 Tyrer, T., & Co., 219. 
 Tyrer, C., 219. 
 Tyrer, T., 309, 419- 
 
 Unverdorben, 4, 5, 70, 77, 97, 142, 186. 
 
 Van Dorp, 211. 
 
 Van'tHoff, 315. 
 
 Verguin, 17, 81, 156, 159, 242, 243, 300, 
 
 316. 
 
 Verneuil, 381. 
 Vidal, R., 194, 272. 
 Vignon & Co., 272. 
 
 Walker, W., & Son, 132. 
 
 Wanklyn, 86. 
 
 Watts, 284. 
 
 Weldon, 214. 
 
 Williams, C. G., 28, 101, 166, 242, 244, 
 
 254, 301. 
 Williams, Thomas & Dower, 245, 
 
 301. 
 
 Wilton, T., 219. 
 Winckler, C., 190, 213, 250, 255, 
 
 256. 
 
 Witt, 145. 
 Witt, O. N., 67, 69, 80, 99, 115, 1 1 8, 122, 
 
 123, 195, 264, 301, 324. 
 Wohler, 411. 
 Worstall, 219. 
 Wiirtz, 51, 178. 
 Wynne, 192. 
 
 Zinin, 4, 9, 65, 77, 142, 187, 238. 
 
 28 
 
INDEX OF COLOURING MATTERS 
 
 Acid green, 116, 192. 
 
 magenta, 192, 228. 
 
 violet, 192. 
 
 yellow, 116, 122, 265. 
 Acridine orange, 194. 
 
 yellow, 194. 
 
 Aldehyde green, 29, 84, 171, 260. 
 Alizarin, 46, 54, 57, 91, 112, 113, 114, 
 116, 122, 134, 136, 177, 178, 181, 
 183, 194, 199, 228, 229, 245, 246, 
 247, 248, 252, 260, 271, 290, 291, 
 302, 305, 369, 412. 
 
 blue, 94, 101, 265, 290. 
 
 Bordeaux, 194. 
 
 cyanine, 194. 
 
 orange, 94, 290. 
 
 saphirole, 194. 
 
 viridine, 194. 
 Alkali blue, 83, 116. 
 Alkaline green, 63. 
 
 Aniline black, 40, 194, 254, 291, 
 302. 
 
 blue, 22, 43, 82, 88, 159, 161, 162, 163, 
 164, 192, 228, 229. 
 
 pink (see Safranine). 
 
 purple (see Mauve). 
 
 red (see Magenta). 
 
 yellow, 122, 124, 192, 228, 253, 260. 
 Anthracene blue, 194. 
 Anthrapurpurin, 92, 116, 181, 183. 
 Auramine, 116, 192, 228, 230. 
 Aurine, 34, 86, 113, 114, II 6. 
 Azodiphenyl blue, 122. 
 Azuline, 35, 83. 
 
 Benzaldehyde green, 84, 88, 90. 
 Benzoflavine, 194. 
 Biebrich scarlet, 116, 123, 265. 
 Bismarck brown, 66, 99, 100, 116, 122, 
 
 124, 192, 228, 253, 260. 
 Blackley blue, 116. 
 
 red, 391. 
 
 Bleu de Lyons (see Aniline blue). 
 Bleu de Paris, 24. 
 
 Blue black, 265. 
 Bordeaux, 100, 116, 265, 291. 
 Brilliant green, 85, 88, 116, 228, 230. 
 Britannia violet, 28, 83, 166, 245, 251, 
 252, 260. 
 
 Cachou de Laval, 194, 265. 
 Carminaphtha, 37. 
 Chloramine yellow, 193, 
 Chrysoidine, 67,99, Io , II 5, n6, 122, 
 
 175, 192, 228, 265. 
 Clayton yellow, 193. 
 Cochineal, 112, 158, 199. 
 Coerulei'n, 265. 
 Congo red, 192, 265. 
 Corraline (see Peonine). 
 Crocein scarlet, 116, 123, 192. 
 Crysaniline (see Phosphine). 
 Crystal violet, 228, 230, 262. 
 Cumidine scarlet, 116. 
 Cyanine, 101, 166, 167, 253, 301. 
 Cyanosin, 116. 
 
 Dahlia, 27, 45, 79,251. 
 Diphenylamine blue, 63, 116. 
 orange, 116. 
 
 Eosin, 95, 116, 122, 175,369- 
 Erica, 193. 
 Erythrosin, 116. 
 Ethyl violet, 166. 
 
 Fast red, 100, 265. 
 
 yellow, 100. 
 Field's orange, 32. 
 Flavaniline, 101, 126, 265. 
 Flavopurpurin, 93, 116, 181. 
 Fleur de Garance, 49, 178, 179. 
 Fluorescein, 95. 
 French purple, 154. 
 Fuchsine (see Magenta). 
 
 434 
 
INDEX OF COLOURING MATTERS 
 
 435 
 
 Gallein, 122, 265. 
 Gallocyanin, 228. 
 Garancine (see Fleur de Garance). 
 
 Helianthine (see Orange III.). 
 
 Hofmann's violet, 25, 44, 60, 83, 102, 
 165, 173, 192, 228, 229, 230, 231, 
 241, 244, 251, 260, 262, 279, 301. 
 
 Immedial black, 195. 
 
 blue, 195. 
 
 Imperial violet, 24, 82, 159, 161, 163. 
 Indigo (artificial), 199, 204, 205, 216, 217, 
 219, 265, 272, 273, 292, 308, 314, 
 316, 323, 369, 412. 
 (natural), 71, 97, 98, 117, 123, 199, 204, 
 
 216, 217, 219, 309, 323. 
 pure, 219. 
 salt, 208, 215. 
 Indoine blue, 194. 
 Indophenol, 115, 117, 123, 265. 
 Indophor, 215. 
 Induline, 116, 228, 253, 260. 
 
 scarlet, 194. 
 
 Iodine green, 30, 63, 84, 166, 170, 173, 
 228, 229, 230, 260. 
 
 Janus dyes, 193. 
 
 Katigene black, 195. 
 brown, 195. 
 green, 195. 
 
 Lauth's violet, 173, 264. 
 
 Madder, 48, 55, 112, 178, 179, '99, 245, 
 302, 323- 
 
 Magdala red, 99, 169. 
 
 Magenta, 16, 17, 18, 19, 20, 38, 43, 60, 
 81, 102, 113, 114, 116, 122, 124, 
 154, 156, 158, 161, 162, 192, 228, 
 241, 242, 243, 244, 251, 253, 262, 
 263, 270, 300, 301, 316, 369. 
 
 Malachite green, 63, 84, 116, 122, 192, 
 205, 228, 230, 231, 262, 367, 412. 
 
 Manchester brown (see Bismarckbrown). 
 yellow, 36, loo, 116, 124, 228, 253, 260. 
 
 Martius yellow, 99, 169. 
 
 Mauve, 5, 39, 76, 121, 124, 149, 151, 154, 
 160, 161, 165, 174, 234, 239, 240, 
 241, 242, 251, 254, 265, 270, 298, 
 299, 3o 
 
 Meister's scarlet, 100. 
 Meldola's blue, 194. 
 Metanil yellow, 116. 
 Methyl green, 63. 
 violet, 62, 88, 114, 116, 192, 228, 230, 
 
 231, 244, 260, 262, 369. 
 Methylene blue, 101, 116, 122, 194, 228, 
 
 230, 264, 271. 
 Murexide, 269. 
 
 Naphthalene red, 170. 
 Naphthazarin, 169. 
 Naphthol orange, 228, 265. 
 yellow, 112, 114, 116, 265. 
 Neutral violet, 265. 
 Nicholson's blue, 24, 39, 83, 163. 
 Night blue, 228, 230, 231, 262. 
 Nitroalizarin (see Alizarin orange). 
 Nitrosophenyline, 33. 
 
 Opal blue, 64. 
 Orange I., 116. 
 Orange II., 116. 
 Orange III., 116. 
 Orange IV., 116. 
 
 Paranitraniline red, 193, 291. 
 
 Peonine, 34, 83. 
 
 Perkin's green, 31, 166, 252. 
 
 violet (see Mauve). 
 Phloxin, 96, 1 1 6. 
 Phosphine, 21, 101, 126, 129, 164, 192, 
 
 194, 228, 253, 260. 
 Picric acid, 33, 228, 253, 269. 
 Pittacal, 176. 
 Ponceau 2 R, 100, 265. 
 Printline, 193, 278. 
 Propiplic acid, 206, 215. 
 Prussian blue, 269. 
 Purpurin, 49, 92, 183. 
 Pyrogene blue, 195. 
 
 Quinoline blue (see Cyanine). 
 red, 176. 
 
 Regina, 163. 
 Rhodamine, 194, 264. 
 Rhoduline, 194. 
 Roccellin, 116. 
 Rosaniline (see Magenta). 
 Rose Bengal, 116. 
 Roseine (see Magenta). 
 Rosinduline, 194. 
 
43 6 
 
 THE BRITISH COAL-TAR INDUSTRY 
 
 Rosolic acid (see Aurine). 
 Runge's blue, 1 5, 79. 
 
 Safranine, 31, 80, 116, 174, 175, 194,228, 
 
 251, 265. 
 Safrosin, 116. 
 Soluble blue, 24, 88, 163. 
 Sun yellow, 265. 
 
 Tartrazine, 265. 
 Thioflavine, 193. 
 Tropaeoline o, 67, 115, 122. 
 Tropaeoline oo, 67. 
 
 Turmerine, 193. 
 
 Tyrian purple (see Mauve). 
 
 Vermilline scarlet, 113, 114, 116. 
 Victoria blue, 90, 116, 192, 230, 231, 
 
 262. 
 
 green, 84. 
 
 Vidal black, 195, 272. 
 Violet de Paris, 173. 
 Violine, 301. 
 
 Xylidine red, 168. 
 scarlet 116, 192. 
 
TABULAR AND STATISTICAL 
 INFORMATION 
 
 Alizarin, annual production of, in 
 
 1869-1873 .... 57 
 chronological history of . . 53 
 Alkali trade production, 1852-1861 317 
 Anthracene dyes, British patents, 
 
 1855-1905 .... 271 
 Azo dyes, British patents, 1855- 
 
 1905 272 
 
 Badische Anilin- und Soda-Fabrik, 
 
 statistics relating to . . 220 
 Bayer, F. & Co., statistics relating to 224 
 Coal, distillation products of. .2, 47 
 products obtainable from 100 Ibs. 
 
 of 13 
 
 Coal-tar, amount distilled for colour- 
 making in 1890 . . . 286 
 weight of various dyes obtain- 
 able from . . . .114 
 Coal-tar dyes, British imports, 
 
 1886-1900 .... 197 
 British patents, 1885-1905 . 270 
 dyeing power of colours obtain- 
 able from i ton of coal . 114 
 German exports of . . .196 
 imports from Germany in 1913 . 319 
 list of (in 1886), arranged accord- 
 ing to origin . . .116 
 
 Coal-tar dyes, list of those produced 
 
 by Perkin & Sons . -251 
 British and German, used in 
 
 Britain in 1865 . . 133-136 
 
 in 1900 197 
 
 statistics relating to . . . 383 
 value produced in 1878 . . 58 
 
 Coal-tar products, British imports 
 
 and exports in 1909 . . 285 
 German exports of . . .195 
 
 German colour works, statistics 
 
 relating to . . . .198 
 
 Indigo, value of world's produc- 
 tion ... 71, 217, 220 
 
 Indigo dyes, British patents, 1855- 
 
 1905 . . . . .270 
 
 Madder, annual imports of . 55> 5^ 
 
 Meister, Lucius & Briining, statis- 
 tics relating to . . 369, 370 
 
 Patents, numbers taken out by 
 
 British and German firms . 198 
 
 Perfumes, natural and synthetic . 384 
 
 Rosaniline dyes, British patents, 
 
 1885-1905 . . . .271 
 
 Sulphide dyes .... 273 
 
 Sulphuric acid and soda, world's 
 
 production .... 384 
 
 437 
 
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